I think what's going on right now is that everyone is trying to establish what the post-war picture will look like. Once that happens, the war will end quickly. Obviously Ukraine won't re-unify since there's no way that the masses living in the Russian-occupied regions would ever want to be ruled over by Kyiv. Every major war is due to a flaw in the international order and this one is no different. I think the big problem that caused this war was the issue of legal abortion and the shortcomings of democracies when they're able to use birth control as a means of population control in order to reshape the electorate. I think Moscow's use of abortion as a means of population control within Russia has resulted in the demographic collapse the country will face which helped fuel the war. Ukraine's use of abortion, coupled with legislation and whatnot to increase its rate in the eastern part of the country ended up sapping those regions of future votes and thus power in a unitary state.
You can't have legal abortion and democracy at the same time especially when the factors that affect the abortion rate are things that can be controlled by the government. That's because existing class, race, or ethnic divisions will end up resulting in the politically dominant group wiping out the future voters of their rivals. Raising child support rates is directly correlated with increased forced-abortion rates and this has been known - and acted on - for decades. Getting rid of anti-natalist policies is a step in the right direction but that can't happen until everyone sees the problems that those policies cause. Once Russia and Ukraine run out of men, then both countries will be forced to change their ways.
So to get back to your point, it'll be a few more years. Both nations have to lose so much that they can break their old demographic policies. Once those policies are changed and they have proof that the old ways led to ruin, then both countries will quickly find a peaceful resolution. Russia can't take over Ukraine since even the eastern part is full of people who hate Russia and are the ones blowing up stuff all over Russia. Ukraine can't destroy Russia since hatred of Ukraine is so unifying that any regime change in Russia would just make things worse for Ukraine. More blood must be spilled and that's the sad fact about this war.