The problem is really alternatives. Give into Russias demands and they will do the same again soon. It will also send a message to China for example and make war more likely in the long run.
What kind of peace agreement would you see possible?
Btw if you’re interested on the topic of the risk of nuclear war related to Ukraine there’s a good video by Lonerbox in which he also explains the logic of the side you’re arguing with here in more detail.