Among other things yes, you can't continue to help if your people suffer more. At some point, you have to pull the plug otherwise you will be needing help. And no, moral high ground isn't going to help you in that case.
There is one thing you forget about.
There are two blocs in the world, one of them is liberal, democratic bloc: USA, Europe, Japan.
Another is autocratic: China, Russia, North Korea.
When you give Ukraine to Russia, you lose 25 million people, your enemy gains 25mln people, enemy gains 1mln possible troops, Ukrainian ammo and drone factories and Russia becames USSR again, a powerful country once again.
Its relatively cheap to give arms to Ukrainians, so that NATO has a safe Europe and safe Europe can assist USA when needed. That was Biden politics.
Clearly Donald Trump has another idea, that Europe should pay for its protection, and its understandable as well.