I know all of this has been said before, but fuck it:
At the end of the day, he just didn't have it in him to go as hard against the establishment Dems as he needed to.
I think the propaganda got to him and he genuinely believes it was his fault that Trump won in 2016 and desperately doesn't want to be blamed again (Even tho he totally will be no matter what he says or does).
What we ideally need is basically a leftist version of Trump (As in not prejudiced, but with the same shameless, boisterous, don't-give-a-fuck attitude).
It's a mistake to think that this happening to Bernie means it will 100% happen to anyone in his mold that tries again. A lot had to go right for Democrats to kneecap him like they did.