I don't think anyone has seen Russia as anything more than a marketing tool for the US war industry exports business.

Prolonging the conflict is more about showing the potential outcome in Taiwan. Limiting support hardware is a show of strategic reserve capabilities.

The Russian economy is a joke. It is slightly smaller than the single US state of Texas. Advanced Russian hardware was a mirage to sell Soviet era surplus.

China has a reasonable economy, massive industrial capacity, and spends 1/3rd the same amount on the military as the USA. It would need to get super creative to buy a win in that conflict.

It sucks to be Ukraine. If it were up to me, give Putin an ultimatum to leave, admit Ukraine into NATO, and give Putin and his cronies a Neapolitan style escape option on an island somewhere remote. When Russia fails to retreat, send everything to Moscow. Its has already been shown that the roads are open.