Stalemate really means an endless civil war until Russia is driven out/forced out or runs out of money/men. Ukraine can carry on to the end of time, they have nothing to lose unlike Russia, that has limited support for their 'non war'
Russia will issue a general mobilisation rather than withdraw, which means Russia will hold on to much if not all of the territory gained
You are deluded if you think Russia can successfully gain and hold on to any part of Ukraine, we have already seen this fail multiple times in the last two months.
General mobilisation is only possible once the area in question is fully under control and secure, but Russia can not achieve that with a hostile nation that are essentially looking for any way possible to eliminate the invaders. They will be constantly under attack. Russia will not even manage that in smaller areas such as the Donbas. Ukraine is not Russia, it will not capitulate - not now, not ever.
I wonder where you get the idea from that you simply move in and mobilise the area?? Russia to date have not achieved that anywhere in Ukraine so far, and for a 'lightening' invasion that was only supposed to last 48 hours I wouldn't say the odds were in Russia's favour, have you seen the state of their army?
Most wars do end with talks, but we are not witnessing most wars are we? We are dealing with a very unstable despot that is showing no sign of reasoned thinking. Most people of average intelligence have given up on the idea this war will end up like most wars. Russia needs to be beaten back, and it is as simple as that. They need to lose so badly it will take generations to recover, that is the only language Putin understands.