If you've been paying attention, they are aware of the crashes and other things introduced by U25. I know they aren't providing information and a fix fast enough for some people but that's how it is. I'm as annoyed as anyone else because crashing every 20 minutes in Cyrodiil sucks, but it doesn't do me any good to be angry enough to raise my own blood pressure over it.
And the mods that review threads are not the same people investigating the problems.
Unless you are a software developer that is familiar with the ESO coding, none of us here are qualified to say what it would take to fix this game or if it is possible
If they recoded the game from scratch with competent programmers who documented everything they coded... deleted the proc sets and sets/skills with tertiary effects... then built it on a modern and capable game engine... and used servers capable of handling the loads... then yes, that would fix the game.
As long as people keep buying reskinned camels, gambling boxes, vanity and housing items from the crown store, there's no reason for them to do anything other than apply bandaids on top of bandaids ad infinitum. Their deluded version of "killing it" is very different from ours.