Decades of NATO higher-ups saying that expanding towards Russia will cause war with Russia,
Nations can join whichever alliance they wish, assuming said alliance lets them. What you're describing here is a condemnation of Russian imperialism, not pushing for war.
refusing Russia’s membership in NATO
Russia never applied for NATO membership, there was nothing to refuse.
and admitting that the war was preventable by Ukraine not pushing to join NATO
By the same logic, world war 2 could have been prevented by just giving the Nazis whatever they want.
Sure, that does make NATO more cautious, but NATO has still been targeting civilians, has been carrying out strikes at nuclear power plants, has been committing war crimes against Russia, all without Russia using nukes
That's not true. Russia has been doing those things to Ukraine constantly throughout the Ukraine war, though.
Considering that Russia has been beating NATO in this conflict, it seems that the only myths that got broken were of NATO’s capabilities against near-peers.
NATO isn't a belligerent in this war. Your statement is nonsense.