Damaging a few buildings and killing some civilians and then leaving seems like the worst possible outcome for Russia, unless the goal is to appear so weak that Ukraine don’t join NATO because they believe they can beat Russia just with their citizens. I like your optimism but it seems unmoored from reality. I hope you’re right though.
The whole point of the war was to sabotage Ukraine prosperity on the long term and increase Putin's approval on the short term. Ukraine and Russia are very close culturally and it's prosperity is a powerful message against Putin's regime.
Undeniably this war is ravaging Ukraine but the sanctions will be far much worse for Russia on the long term. He already lost on all his goals. If Russia doesn't agree or at least move forward with a ceasefire today this will be a signal that Putin is really insane.