Zelensky is dead either way, but peace lets him flee somewhere, and claim to have done the right thing.

Zelensky's dilemma is that his real powerbase are the militant ultranationalists who surround him, who make up a double edged sword for him. Even if the Ukrainian people would have wanted peace yesterday they are not armed or organized. Zelensky still needs the nationalists around him to stand between him and possible popular uprising and the more moderate wing of the army doing a coup. If Zelensky goes for peace he fears that the nationalists around him will see that as an betrayal of Ukraine, them and those who have sacrificed their lives for their project and will turn on him and arrange an "Russian missile strike" in his office that will kill him and end any negotiations. You must understand that despite being called nationalists, the banderites love their imaginary version of Ukraine more than the actual nation. Ukraine bending the knee to Russia would save the real Ukraine, but it would destroy their ideal version of it and doom and taint their idea of Ukrainian nationalism forever.