We need to look at this from a Russian perspective and taking distance
Will Putin trust immediately the US because Trump is pushing for that? What are the guarantees for Russia that sanctions won't be reapplied when Trump will go away? No guarantee because US congress decides for that, all the relief that he would get would go away once Trump gets out
Where will Ukraine go? Billions have been invested into this war and weapons are already delivered, all of this to stop Iran to acquire 4th gen fighters and reduce trade?
Trust will take decades to rebuild, what they did with Ukraine is and was massive, the anti-Russian propaganda, the dehumanization and insults, rewriting Russian history, personal insults to Russia, threats to nuke Russia, scamming Russian people, operational help with awacs plane to target Russian troops etc
Remember when Iran demanded guarantees to the US that future presidents respects JCPOA, the response that Iran received was Trump illegally breaking the deal by surprise