Would a AOC presidency really be a existential threat to the revolutionary left?

I'm not American and not super invested in US politics apart from watching the Empire slowly die, I also believe all democrats are cringe, however I don't understand why people are so invested in stopping the Aoc/Bernie lib momentum. Yes socdems killed Rosa Luxemburg, but you Americans have no Rosa Luxemburg, As long as the socdem can't stop the imperial decline, (which in 4 years time will be beyond her,) Idk why you guys should be so anti social fascism you end up preferring non social fascism. Social democratic policy could at least ease support for reactionary sentiment, like if Stammer was a Socdem he would still be an imperialist but at least he would not be pushing austerity that is leading westoids not to socialist orgs but towards the Reform party. Of course it's bad if she actually pushes enough leftists towards organizing with democrats instead of revolutionary's, but the whole "we would have made our own first world revolution by now if only if wasn't for those pesky reformists" feels like a easy explanation for the failures of the western left, especially considering how many people who are anti imperialism zionism and capitalism today such. Jt of second thought was literally brought to where he was today by kibbutz Bernie, people seemingly want to forget this.