Look at the population of Russia and Ukraine. Even with endless material Ukraine is going to run out of a meat puppets long before Russia.

Unless the Russian economy collapses first. The ruble has lost 10% of it's value in just the past week. Inflation on many items is near 70% despite interest rates currently being set at 21%. It's spiralling a bit recently due to a renewed wave of sanctions enforcement and tanking petroleum revenues.

Now, that doesn't mean it will collapse, but it does mean they can't keep doing this forever. Number of soldiers available isn't the only factor that decides whether a nation can sustain a war.

Plus their other geopolitical projects are starting to crumble a bit. See: current events in Syria.

It's Russia that requires Africans for it's jobs and North Koreaans/Syrians for the war ( with very high pay)

Invading leads to more casualties than defending.

Not if they have enough materiel to kill at a 4:1 ratio or better.

So it builts robots. Ratio is already 5/1. Never give in Giving in got us here!

Yeah but look at that border with NATO that Putin keeps manned. He cant just dump his entire military into ukraine like a lot of pundits predicted.