I think they might be more useful as anti tank weapons. Russian inventory has taken a beating, may as well top up any way they can. There's gonna be tanks heading towards Russian/DPR positions sooner or later. In this war, or the next one.
For Putin, this war is everything, so he's going to pull out. 
- the things you learn on Twitter.
It's true that the US can make money printer go brrr longer than Russia can fund its war effort, but Europe can't afford a long war. It's economy is already under huge strain, and Euro participation is necessary to NATO's proxy war effort. And, while Ukie resistance has been impressive, there's only so much death and destruction a country can or should take. Easy for Western faggots to encourage Ukies to get their limbs blown off and their infrastructure to get bombed forever, but what's in it for Ukraine?
Donbass has been threatening to turn into a full scale battle for weeks. Assume it happens, and Russia wins, then declares "victory" and sits behind its new borders. What does Ukraine gain from continuing to throw men at the line of contact? That just means more body bags and more missile strikes on western Ukraine.
Unless the mythical Ukie master plan to drive out the Russians turns out to be real, and it doesn't look that way - at some point they're gonna have to figure out a way to get back to some kind of normal life unless they plan on being Slavic Somalia.