1.) It's not a new technology. Like kamikaze wasn't a new technology. She just deciding to ram her ship into theirs ASAP to give the rebels as much time as possible. She had no idea it would work.
Tracking IS a new technology. That is literally what they say. Nobody ever made something that enabled you to track someone in Hyperspace, and First Order did. She could have no idea she could ram them, and yet "she decides to ram their ship".
Just to clarify, fleet combat has 100% taken place at greater effective ranges in Episodes 3 and 6. To be fair, Star Wars isn't the best at giving an accurate sense of scale in space combat so it's kind of a moot point--the range is pretty much always determined by plot. That said, the whole barely being able to outpace ISDs is an absolutely bogus looming threat. A.) No. B.) You're telling me that Mega Star Destroyer can't shoot for shit? Ridiculous. \
They literally say in the movie that they are too far away for their guns to work, which is why they are pursuing them in first place and waiting for them to run out of fuel instead of just, you know, gunning them down. Fuck scale, fuck that, I am going off what characters and plot tells me.
Again, there's nothing that makes hyperspace ramming any more effective than IRL ramming.
There is. Speed. Unavoidability. I will also say power, as with the speeds Star Wars capital ships seem to operate, I wouldn't say they should be able to literally cut something that seems to be at least four times as long as regular ISD in half.
If you were to steer an aircraft carrier into a fleet of ships you'd fuck them up pretty bad before sinking (or more realistically, being immobilized). You have lost out immensely by doing so, given the value of the aircraft carrier.
She destroyed biggest fucking ship in Galaxy, a capital of First Order to that and multiple goddamn ISDs on steroids using a ship that was magnitudes smaller. That is if a cruiser rammed all American carriers and sunk them at once.
She won. Not only have you damaged your faction up on the strategic level by losing such an asset, but the sunk cost (pun intended) of the carrier is greater than that of the ships you murderfucked. But if it was the decisive battle of the war, the carrier's planes had all been shot down, and the only useful bodies and craft left were being picked off by those enemy ships? It's a different equation.
The cost of the ships she murderfucked was much higher of her ship. Sure, technically it is a loss for Resistance, since they have only one, but in regular combat between similarly sized fleets sacrificing one goddamn cruiser to destroy entire enemy fleet whereas normally you would probably have to deal with loss of many more due to regular combat is great fucking trade.
Hyperspace drives are probably the most expensive parts of any ship and have to be scaled up with the size of the ship as well. Shooting a ship with a small hyperspace weapon is only going to be catastrophic if the ship is, say, less than four times the mass of the hyperspace weapon. Otherwise it's going to be like getting shot but having your organs missed. Bad, yes. Fatal, not really, and military vessels are going to have substantial damage control systems. And once you've done this, you've blown your space load on that part of your force, it's gone. Blasting down the shields and shooting with blasters and missiles is going to be way more cost and force efficient.
But the enemy will also be shooting back. This is why I said hyperspace weapons probably aren't an "I-Win button", but they should be considered in universe as something that has it's own applications. I don't think the hyperdrives are even that expensive, considering they slam those in X-Wings, and also if you're worried about the cost of losing a whole ship, just put a hyperdrive on a fucking asteroid or something.
Ramming is like defibrillators. Fiction and intuition tells us that it's cool and dramatic, so it must be useful. But it's really not. The Raddus was in a nearly unique tactical situation to make a hyperspace ram of the Supremacy worthwhile, and did so almost as soon as those circumstances fell into place. It would have been an incorrect or at least less correct maneuver in every other Star Wars battle to date, including the assaults on both Death Stars and the Starkiller.
Unique tactical situation my ass.
1) Supermacy could have hyperspaced small projectiles to destroy Resistance engines, since from rear that should be relatively easy and they couldn't dodge at all.
2) Hyperspace bombard the ground shields on Endor. Death Star now has no shields.
3) Hyperspace attack the Death Stars, with first one just attack near where the laser is to disable it and finish off the star with regular means, assuming the damage wouldn't be bad enough to kill it, and with second one that is literally half open to space just ram that fucker straight into the basically exposed core.
4) Hyperspace attack the Droid Control Ship in prequels.
And so on. The problem is IRL ramming is cool and dramatic but it's not really that useful, mostly because you can be destroyed by regular means before you ram (although a case could be made that literally all missiles are more or less ramming devices, just with explosives strapped on them). The problem however is that hyperspace ramming is pretty much instantenous, so it can't be really defended against.
Equally so, this is quite clearly a very rarely used technique. If it became more common, tactics would adapt, much like a ship in the sea throwing off a firing solution for a torpedo from a sub, the ships would start changing their course and speed erratically to avoid it, or find some technology to negate the effects, like having an interdictor cruiser standard in every fleet, or even just gravity well generators on enough ships to make it untenable to commit resources to specialized rams.
This is the exact fucking point. Why it's rare? Why it's not used more? It is clearly something that they realized could happen, but did nothing to counteract it? They act like universe is completly aware this can be done, but then everyone is fucking suprised to the core it can be done.
She guessed and was proven right by getting blown apart/the force told her/everything was lost anyway so may as well try/she was an idiot who had never heard that hyperspace ramming doesn't work usually.
And you're telling me in the long-ass time they hyperspace drives existed (EU be damned, the Republic was said to be old as fuck in regular canon anyway, so they had hyperdrives for at least this long) nobody tried it?