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).
I think Bernie could have ran an effective tactic of recording his meetings with CEO executives and leaking them to the press about how adamant they were to kill poors.