I rather suspect that derived-from-a-human is pretty much the same as being human. There is no "we spend all our free time singing in trees" or "oh, my great to the tenth power grandparent? They live a few blocks down that way" nor "This is my tree, I live in it, if it gets hurt then I get hurt". There is just "this is what sort of human I was, now I am exactly the same except I have some contrived secret-society styled excuse to get into adventures and drown in angst because I have to eat people or something and oh noes I lost my oh-so-precious humanity waaah boo-hoo waaah..."... Now, granted, that all falls apart almost all the time because dwarves are just short Scots and elves are just French-with-ears and it all turns into a great big exercise in attempting to have legitimised racial profiling and arbitrary extremes of parenting to angst about escaping, but the principal remains...
Still, High-fantasy is more about possibilities. Death not being a big deal is pretty solidly high-fantasy, but combined with a tedious existence where there is no real significance to it other then a game-mechanic to ramp up the trial-and-error without forcing people to start over from scratch over and over leaves it kind of under-utilised. The Lord of the Rings was much the same, highly fantastic things were possible, but they didn't really occur with any volition. Most of it was just worrying about supplies, somewhat mundane espionage, and assorted forms of diplomacy with folk who either already wanted to help or had some specific reason to get involved. There was lots of high fantasy in the history and a lot of "boom, high fantasy flew you over the forest, now get back to crossing the mountain range on foot" But the setting was still basically just farmers farming, soldiers swinging swords and shooting arrows, and assorted nations getting into fights over land, history, and religion...
To my mind, high fantasy is about making your characters more capable. Mundane terrain shouldn't be a problem unless there is something fantastic and very specific that is causing it to be a problem. The assumption should be one of a post-scarcity society, and if you want to make it grim and oppressive then you need to add it back in. not that it is all that difficult to ad it in, throw in a few despotic super-mages and a horde of monsters and perhap an apocalyptic legion invading from an alien world and throw in a few all-powerful rocks that have various exciting effects like "in this nation, the floor is literally lava, bring a hammock" or "no magic here" or "don't ever make a goat angry" and you should start to see all sorts of grim oppressiveness where you could get rid of all your mundane issues and live in perpetual bliss if only all these massive disasters didn't keep bringing down the mood...
But really, if you want grimdark with permanent flight, constantly regenerating stamina, magical restoration of all your ailments, and all manner of races scattered around the place, why not play Morrowind?