Does anyone truly believe Russia couldn't have completely annihilated Ukraine if that was their goal? Russia wants as many Ukrainians to accept being a part of Russia, without Putin destroying everything. Until the EU stops purchasing fuel from Russia (and they're going into winter) and gets tuff, this chipping away will remain the goal of Russia.
The Russian people also play a huge part in this and fortunately it looks like they're starting to. Putin needs to be overthrown.
Russia tried and failed in Afghanistan, and ended up withdrawing... the US then stepped in, until it too gave up and withdrew.
Yes, short of using Nuclear weapons, Russia threw everything it had at Ukraine... and failed - getting stuck in an ongoing war of attrition.
The continued attacks on civilian infrastructure including civilian homes, shows that Russia has a total disregard for Ukrainians and really doesn't care about them becoming "Russians" - Look at Stalin and the Holodomor, if you want to understand Russian attitudes towards Ukrainians.
