Putin doesn't want Ukraine. He wants a legacy. Trump will be forever linked to Jan 6th. What is Putin's legacy? Crimea?

Sad Vlad wants to be remembered for something. Ukraine is the key to his legacy.

That being said, if he was 'removed', I'm pretty sure his underlings, who probably don't give a single fuck about Ukraine, would try as quickly as possible to restore Russia to its pre-invasion state. Plus the oligarchs would outright demand it.