The Bernie Bros who voted for Joe Biden have gotten royally f***ed for the past six months: the $15 minimum wage (the big structural change is gone), Medicare for All (which was never happening), the public option in health care (which was promised) and above all else on student loan debt. There is nothing stopping Joe from doing that one except his own unwillingness to so.
Regardless of you feel about the issue, you can recognize that student loan debt forgiveness was a big reason why college-educated Millennials with student loan debt voted for Joe Biden. They wanted to get out of debt. It was one of the key issues that caused them to get off the couch. Chuck Schumer has been giving Joe Biden a hard time for months now for not doing shit for those people.