I would say this really stupid.
For one she wasn’t much of a leader. Leaders know what they step into. They don’t do absolutely stupid mistakes like her omg I’m 0.1% native American because I did a DNA test.
Then, and quite importantly, she was an ex-corporate stooge and Republican supporter that reinvented herself as a leftist Democrat. She had quite an ego to go against a lifelong leftist Bernie’s consistency of ideas (oh, I adopted a few bullet points along the way but I would be better at doing it while going against someone who planned them for what it seems like a lifetime). And against a couple of lifelong Democrats that didn’t jump boats.
Finally, she wasn’t attacked more or less than any other candidate. Even the much touted ‘electability’ idiocy is the same thing flinged at Bernie from the start (as well as at Buttigieg in some circles).
But sure, let’s cry over the fact that she’s a woman, let’s not mention her inconsistency over what kind of candidate she wanted to be. Yeah, her policies were clear and nice but Sanders overlap aside (you don’t get points for adopting the stuff that the guy next to you has supported all his career) she kept shifting her stance on how to do it. Go hard at corporations but then shift a bit back so as not be too divisive. Try to be a balanced unity candidate but still reconcile that with some hard left ideas in a way that won’t sound as if she’ll cave at the first compromise along the way.