A result of a loss of manpower and eventual loss of political will to continue the war. The parts that Russia controls aren’t coming back to ukraine except maybe the last 30km where russia hasn’t set up proper defences.

It’s about who has a reason to continue fighting, and as you’ve suggested, who has enough bodies to maintain a functional army.

Russia’s 9/11, that’s what I like to call it. Bombs in the buildings.

I hate to tell you this but it’ll probably end with putin alive and ukraine ceding territory.