AOC? Nah, she's been made to heel to Nancy's and Hakeem's wishes. Buckled at pretty much the first opportunity too. Still says some nice things, but she's useless as a challenge to the status quo. Made a useful tool of the establishment.
Bernie? Well, he tucked tail and quit fighting after the party establishment colluded and sabotaged his campaigns. 2020 was especially egregious, and he still agreed to back Biden. Again, says the right things at times, but far less a real challenge to the status quo now than he ever was.
The others you mentioned? Mamdani can be a good pragmatic example, wish him the best, but he's limited to the Senate at the federal level if he aspires to higher office. El-Sayed, too early to tell. Talarico, I assume you mean? Tough row to hoe for a few months, probably a long shot, but he's been a democrat for years. That party is really irredeemable.
I wish I knew the real solution to this electoral mess. I keep hoping for a really hard charging third party challenge that can bridge the divide. May wait my entire life at this point.
Bingo.