Ukraine cannot join NATO if Ukraine does not exist.
It is now obvious that the real objective of this invasion is to erase Ukraine from the map and annex it to Russia. Everything else is just false justifications or lies.
That's why Russians do not care how many Ukrainians die, they don't care how much damage they inflict, they don't care what is the opinion of Ukrainians, and they definitely don't care about NATO or the West or anyone else. Their objective is very simple: to conquer.
It is old time imperialism. In past centuries, other countries may have joined the war by now, for example Poland or Japan, but nowadays they will not, because of the fear of nuclear weapons. This war is actually easy for Russia, compared to their other wars in the past 500 years, because they know that nobody will attack Russia itself. This is the wet dream of any imperialist: attack with impunity! If you win, you won new lands, if you lose, you are guaranteed not to lose any lands! This is the first war of this kind. America had a lot of wars in the past 60 years, but they never had the goal to annex new lands permanently.
Russians believe that if they conquer Ukraine, then sooner or later the West will accept the new reality and everything will return to normalcy, including trade, western companies etc. And of course, they know that NATO will never ever attack the Russian army directly, no matter what they do to Ukrainians. The Russians will escalate this as much as they want to, till they win this war, that's their plan.
I hope that Ukrainians can win, but it seems quite difficult against such a ruthless opponent. It seems to me that if Russians start losing on the battlefield, and I mean really losing serious ground, they will just escalate further, using chemical or tactical nuclear weapons. After all, what is the difference? They have already bombed civilians, shopping malls, they have deported millions of Ukrainians. They are already war criminals ... but nobody can arrest them. Will any further escalation make any difference? This is much worse than Afghanistan. They did not deport millions of people from Afghanistan to Siberia.