I would expect immortal races to be pretty useless for innovation, but culturally inclined to megaprojects and the skills commonly employed in megaconstructions. Immortal races don't live under the constant threat of impending doom. They lack that essential impetus to find ways to do things better and faster, and have more to lose from taking reckless risks trying to find a better way. On the other hand, they're likely to still be around to appreciate and reap the benefits of an undertaking that requires decades or centuries to complete. They're also probably more likely to do things by tradition, the way they've always been done, because they have the memories, not just vague stories distorted by multiple generations of retelling.
People who know they're dead in 40 years no matter how safe they play it, and have only the faintest idea of how things were even 200 years ago, are the ones more likely to be trying new methods and finding new solutions.
I don't think that's the real problem.
Elves won't advance technologically because they don't
want to. They are
happy living in peace with nature, sitting under trees that drop orchard fruit on the ground that they can just pick up and eat and talking to animals and smoking every random plant that can give a high rather than having to actually do hard work for a living.
Why give that up for the life of a dwarf, which tends to involve living in a cave filled with pus and blood, eating mushrooms, and working at a choking furnace only to be killed when the little psychopath next to you finally snaps and beats you to death with his own leg?
Goblins have more reason to innovate, since they are in perpetual competition, but also more reason never to share their innovations, and since the leaders are the strong, they'd have reason to destroy any innovation that might give anyone else a better chance at equalizing power. They are inherently hoarders, not innovators.
This brings me to the real, overarching problem about the way that people think about technology.
To start with, destroy this notion that we all have because of our modern world that
everyone agrees technological progress is just a given or that it's always good.
Technology isn't a timeline of constant gradual progress. Humanity stayed in Medieval Stasis for so long
because it wanted to. Technological advances were mostly thrown away by the peoples who invented them because they hated the implications of social change they would bring about, and preferred a stable status quo to unpredictable social upheaval.
It's only Europe, with its constant infighting, that ever developed labor-saving techniques (because labor was in short supply after the plague) that would disrupt the social status quo specifically because they were afraid the other European powers would do it first.
Compare this to Japan, which were the premier firearms manufacturers of the world in the middle of their Civil War, which then outlawed all use of, possession of, making of, and teaching of the techniques of manufacturing firearms except under explicit imperial permission (which was never given) until they forgot how to make guns. The functional ruling class of Japan were the Samurai, and the gun was DEEPLY offensive to their whole worldview, which saw martial discipline as the greatest of goods, and the notion of a weapon that any random peasant could use to kill even the mightiest of warriors shook them to the core, and as such, they tried to eliminate it entirely from their culture.
Keep in mind, Star Wars was originally based on the old Japanese Civil War, Sengoku Jidai, which is why the Jedi (note the name similarity) Obi-Wan introduces lightsabers (katanas) by saying something that makes no sense in Star Wars, but perfect sense in Sengoku Jidai - "An elegant weapon for a more civilized age." That is, a time before guns interrupted the status quo of samurai (jedi) being the undisputed rulers of the battlefield. Notably, blasters
always existed in Star Wars, no matter how far back in the timeline you go, (lightsabers are actually something that may have been invented AFTER blasters) so it's not like everyone had lightsabers back in the day. The entire fact that jedi can deflect blasters comes from the myth that samurai could deflect bullets with their sword - something samurai claimed in an attempt to try to reclaim some of their lost mystique after guns were outlawed, to try to help justify their status.
The same goes for MANY instances of Chinese history. Because China had no rivals as an empire, they could backslide technologically as much as they wanted, and often did so for trivial reasons. The first (maybe) Chinese emperor famously started his reign by declaring that all history before him was crap, and ordering all texts from before his reign burned. Every successive dynasty would try to delete from history the great works and inventions of the dynasty before them to make themselves look better.
The story of Zheng He is one of the most illustrative - China created a massive super-fleet in the 15th century, led by an enslaved Arab eunuch and close personal friend of the emperor. This fleet would have absolutely curb-stomped the Europeans that would later come and force China into humiliating subservience to England and crippling opium addictions foisted on them by the English who wanted a nice, docile colony. This super-fleet was capable of traveling as far as the Cape of Good Hope and possibly California, and created in the Chinese Imperial Court a sort of early Asian U.N. All the other nations of the Eastern World came to pay tribute to the Emperor of China.
Then, when the emperor died, the next emperor was a nativist who hated all the foreigners walking around, so he banished them all, ordered the whole navy destroyed, ordered all the shipwrights murdered, and all the literature on how to build the boats burned so that China wouldn't deal with foreigners anymore.
Even in European history, many great labor-saving devices were constantly thrown out specifically because "but if we save on labor, what will we do with the slaves?" (Which is why slavery is such a horrific retardant upon scientific progress.)
Stories like Dr. Faustus and even later Dr. Frankenstein (in their original versions) were about how
education and science itself was inherently evil. Faustus was a doctor, and learning about medicine and how to cure diseases, itself, was a Deal With The Devil. Faustus in many versions even explicitly used his knowledge
only for good, and was still considered evil simply for knowing science. That's the point of the message - not even if you use science to help people will science ever be good.
When the plague swept through Europe, it didn't take them long at all to create a printing press. Just a couple decades. They could have made it
at any time they wanted, but then, they had plenty of scribes, so why bother? It was only when they ran out of scribes that they created the printing press. They merely never
wanted scientific progress before that time.
Even in the modern era, we don't advance technology when we don't really want to, when we're comfortable with the old technology.
Thomas Edison was creating electric cars back during the early 20th century. Sure, they were clunky and unreliable, and needed constant charging, but they were under serious development and people were using production models of them. But then gasoline prices dropped because huge reserves of oil were found under Texas. Why bother with electric cars, when they're more expensive?
We could have been 100 years more advanced with electric cars by now if only there hadn't been oil under Texas, or we had been less willing to just rest upon the technology we had instead of having a desire to innovate.
Now, let's go back to Japan for a second. During their Edo period after the great civil war (Sengoku Jidai), they stayed in (completely purposeful) medieval stasis for centuries. They almost completely isolated themselves off from the world, and quashed any technological development for the explicit purpose of preventing anything that might disturb the social status quo. (The eventual winner of the civil war was a peasant who eventually came up to being Shogun through sheer talent and ruthlessness... and lived in constant fear of social mobility that would cause someone else to be able to do the same. So he created an incredibly strict caste system and basically outlawed any contact with the outside world or new ideas that might disrupt his perfectly stable garden.)
Then the Americans, fearing how much power Britain had because of making China their bitch, decided they needed an Asian trading partner, too, so they sent Commodore Perry to kick in the front gates and demand they modernize and start trading with America at gunpoint. Because Perry apparently "forgot to bring" the opium, Japan actually managed to explode in technological prowess in a few short decades, making a leap in 50 years that took 1,000 years for Europe to make. (Thanks in no small part to how stable their society was and how centralized their government was, the strong government, when it actually wanted to enforce social change, was capable of doing so fairly rapidly.)
Sure, they had help, they had someone to copy... but so does the whole rest of the Third World. It took them just decades to do something that many other nations invaded by Europeans haven't been able to do
ever. That's mostly thanks to the fact that Europeans purposefully destroyed the nations they conquered (while Perry forgot the opium) in order to make sure they were captive markets that would be easily monopolized by the already-established mercantile powerhouses of the home countries of the Empire.
Really, the whole reason America broke off from England wasn't because of something silly like "taxes", but because of what those taxes were meant to do - cripple American industry, and force America to be a captive market for English goods. They treated the American colonies the same way they treated the other colonies in the empire, and the Americans found it so offensive that they wouldn't be treated as British, but as those other, lesser, colonies, formed of other, lesser races, that they revolted.
So no, don't go assuming technological progress is assured. Don't assume that, if you created a parallel world where some aspects of the planet were different, and you watched human history unfold, you'd get the same technological progress at the same rates.
In fact, one of the more sure factors of technological progress is population density.
Islanders almost always backslide technologically so long as they have populations of less than 500 people. It's simply impossible to maintain technology and ideas, even basic ones like boat-building that they'd need just to get to the island they're on, with less than a certain amount of population.
Meanwhile, technological progress and the rise of cities almost always go hand-in-hand.
There's a
reason Sid Meier's Civilization bases all technological progress off of cities, with the surrounding land merely existing for cities to extract more resources. Sid Meier is an ardent believer in this view of history. And notably, with the right situation, you can hit the Space Age by the year 100 AD or so.
The reason why so many inventions were abandoned throughout history? That it would have left the slaves without jobs, or that it would have left workers without jobs, etc. They're still reasons we don't use inventions today - every time a new labor-saving invention comes out, there's outcry over all the jobs it will kill. And technology DOES kill jobs... it's just that in a city that can infinitely consume and infinitely produce, there will always be more jobs to be created, and the capital that can be raised through the labor-saving devices are worth it.
(And remember, the super-high-tech iPhone? Assembled by hand by Chinese near-slave labor... because it's cheaper than building a robot that can assemble an iPhone.)
Necessity is the mother of invention, and without the need, technology is thrown away as some evil job-killing disruptor of good social order.
If we're going to build a world with dynamic technology levels, we need to actually model the reasons why technology is adopted, and more importantly, why it's
rejected so often. Technology backslides as often as it advances, and it's only a very recent and very strange anomoly of a time we are living in where technology actually does advance and people actually think of it as a good thing.