Warren can go fuck herself, She was one of several that backed out of the 2020 race to kneecap Bernie Because he was projected to win the Democrat nomination. People like Warren fucked all of us.
FWIW she actually didn't back out with the moderate candidates before Super Tuesday. She did after splitting the progressive vote between her and Bernie, giving Biden the win.
You can pretty much lay blame on anyone or anything because there's absolutely no way to prove it one way or another. You might as well be saying Biden got elected because of the phase of the moon.
I'm claiming that people employ binary thinking and lay blame where the answer is just a wee bit more complex. Saying "Her selfishness is a direct cause of Biden being elected." is flat-out ludicrous for all kinds of reasons, mainly that no one knows what would have happened if Bernie had been the candidate. Nobody's even putting numbers on what "split the vote" even means. FFS.
And look, I voted for Bernie. I even wrote him in in 2020 (I'm in CA).