Whether he's done good or not, it doesn't help if he doesn't fire up his fan base. Even before he fumbled (pratfalled) so badly on the Palestinians, Biden was not firing up the fan base.
Nobody in the Democrats was. Because the Democrats systematically ousted anybody who could.
Nobody who counts in an election—the voters—was fired up by the Democrat messaging and now they're paying the price. Enjoy your four more years of Trump.