The PPP loans were specifically designed by legislation to be forgiven. Student Loans may not have the case, as the act that empowers the Dept of Education/Biden/Whoever to waive loans also says that they only get that power if it is vested into them that they should do so from Congress.
https://www.reddit.com/r/politics/comments/rmh0sb/sanders_urges_biden_to_cancel_all_student_loans/

