The Russian army is actually smaller than the Ukrainian army with respect to what Russia can effectively deploy and maintain in Ukraine. So, the real question is how long before Russia packs up and leaves if it cannot negotiate a peace where it keeps some of its ill-gotten gains.
No one is winning, both Ukraine and Russia are suffering horrific losses, but the longer the war drags on the more Russia is at risk of collapsing and slipping from an almost superpower to a "has been" superpower.
Meanwhile, like China and Iran, but for different reasons, the world is learning to live without Russia and as a country whose economy depends on exports, that can have drastic consequences longer term. Again look at the what has happened to the standard of living in Iran and what is happening now in China as companies rush to relocate their supply chains out of China to other countries.
Russia has lost. Now the question is, how will it play out. I don't think Putin will survive much longer, the war has no purpose other than to kill Ukrainians and Russians and with Russia's low birth rate, that is a dagger in its heart.
Check out a map, does Russia need any more land... now check demographic trends... Russia is losing people rapidly... does it make sense Russia is trading lives for the hope of gaining more land and then having to expend additional lives keeping the land they stole.
Check out the link below for Russia's population trends:
https://www.macrotrends.net/countries/RUS/russia/population
Overlay a shrinking population with an aging population and Russia will have trouble holding on to the territory it has, much less Ukraine if it should gain territory there from this war.
With around 15.7% of its population aged above 65 years in 2020, Russia is considered to have an aging population. According to the World Bank, the age dependency ratio, defined as the ratio of people older than 64 years and younger than 15 years to the working-age population (between 15–64 years), is around 51.2% in 2020, up from 38.9% in 2010.
