Even in the event the US would win a direct war against Russia
The US would not win a direct war with Russia, unless it was hosted in Germany or France maybe. It'd be the biggest slaughter of Americans since the Civil War.
US troops are better trained, better equipped, and have better logistics. Morale might be better too, tho its been declining for years along with basic fitness standards. None of that will matter once the tac nukes turn US bases into crispy salsa and it becomes a WW2 style knock-down fight against an adversary that understands modern war. The relative restraint Rooskies have shown so far stops immediately as soon as the first Abrams rolls across the Ukrainian border - Rooskies would (correctly) interpret that as a war of national survival.
The late Cold War / early 2000's US military would've crushed the Warsaw Pact in a Tom Clancy approved orgy of combined arms before or after the ICBMs made victory basically irrelevant. Current US military has spent 20 years doing counterinsurgency without achieving much success other than to rearm the Taliban and make Iraq best buds with Iran. It's not the same army anymore, it's a lot weaker because the men and women LARPing as men are weaker than the guys from 1991 and 2003. These are the kids who grew up with safe spaces and limpouts if someone called them a gaylord. They'll get pregnant before deployment, or they'll break in the field because they'll be facing a level of brutality and desperation not seen since Vietnam and Korea, and nothing in their training or background will prepare them for that.
Russia would easily raise hundreds of thousands of fighting men to fill out their ranks, and China would gleefully pump out weapons and supplies to equip them, for the same reason the US is arming Ukraine. But if the US tried another draft there'd be riots. Doesn't matter how much Facebook Boomers and Reddit hate Russia - Zoomers, Mexicans and Blacks aren't gonna be lining up for the chance to die in a muddy ditch in Slavholistan for funny foreign meme president or creepy senile fraud president. And there's no reason why they should. They have their own lives to worry about and this shit doesn't concern them. If Pearl Harbor or 911 happened tomorrow the MSM would be beating the war drums and turning the patriotism up to 11 as usual, but this time half the country wouldn't believe them.
That's why we're fighting to the last hohol. There's plenty of people in DC hoping to escalate this into the open war with Russia they've been fapping over since 2008. But they're think tank faggots, neocon pet politicians and fast-talking, flabby ex-Soviet Jews with a weird little hateboner for the country of their birth. Nothing the Pentagon has said indicates they want to get into the middle of this fight, because they know better.