Russia does not have the resources for that. A reminder this isn't a proxy war for them, even though it is for the West. Russia is there in person conventionally and is somehow losing to a minor Western ally.

The Ukrainians aren't going to run out of stuff within the next year for sure, and maybe not ever because even if the US gets bored Europe is highly invested. Russia has negligible productive capacity of it's own, and is bound to have serious problems eventually, unless they convince China to help and China has so far been uninterested. They could theoretically win by population attrition, I guess, but nobody's really talking about that yet. And, to do anything, they need political stability, after already having one mostly-failed coup.

Imagine liking a queerphobic dictatorship.

It's not just the US though. The European powers are far more firmly committed. It's not at all clear that the rest of NATO will simply walk away if/when the US does. Especially the former Soviet nations; this is not a fucking game to them. The loss of US support would be huge, but I don't see a universe in which the Europeans just roll over for Putin once the US loses interest.

It's an investment, remember