That's exactly the Ukrainian plan as well, at least when the negotiations were going on.
With one important difference:
Russia goes back to February 23 LoC and doesn't get to keep its' current advance. And this happens now, not in some "future multilateral peace treaty."
And one doesn't even need negotiations to actualize this - Russia can just announce that they are going back to the previous LoC and just do it.
Since Putin's entire foreign policy is basically invading the "near abroad" and adding territory to RF, this would seem to be a non-starter for him.
And more context on the sudden renewed European push for ceasefire at any cost:
BBC News - Ukraine peace deal: Kyiv rules out ceding land to Russia
https://www.bbc.co.uk/news/world-europe-61542090