Your net search has missed a key consideration. For successful peace talks,
- either one side has clearly won, and the terms of the defeat imposed on the other side are formalized,
- or both sides are equally matched and both found that neither side can win,
- or the conflict is not a vital national interest for one of the sides and they look for a face-saving way out when it becomes too expensive to win,
- or a third party is willing and able to impose a settlement on the belligerents.
There is no clear victor yet, but both sides seem convinced that they can still win. Ukraine has held out beyond most expectations, made some successful counterattacks, and inflicted heavy casualties on the Russians. Russia is vastly larger than Ukraine, it is a nuclear power, and almost all the fighting has been in Ukraine, not in Russia. Russia also inflicted heavy casualties.
The Russian government seems to see a victory as a vital national interest. I cannot judge if they could politically survive an 'unsatisfactory' outcome, but Putin might fear to end like Ceausescu if he steps back. For Ukraine, victory is also vital.
No third party can impose terms on the Russians. Terms could be imposed on Ukraine by the threat of cutting of aid, but that is not in the interest of the West at this time. (If Ukraine were to counterattack into Russia, their support might evaporate quickly.)
This armchair analysis matches what the FT writes about the Russia-Ukraine war.