I think this is just about setting the legal precedent, make sure that there are official negotiations more recent than April '22. This refusal will certainly be referenced in the future when they will make further demands using this as a justification i.e you had the chance, you refused and caused even more harm, therefore we are in our right to demand further compensation.

There are also other factors to consider, the situation for Ukrainian civilians is getting worse, electricity is almost completely out and it is going to get much worse. Putting an official record that Russia is willing to end the war now is certainly going to affect a significant part of the population.

Obviously its not like stupid democracy shit is real at all, they're not going to protest their way into a peace deal with Russia, but this can lead to civil unrest which means even less manpower which just ultimately means Russia continues to steamroll.