"By official decree, all education shall now be free, and all debts accrued for the purposes of education are forgiven. If this should result in the dissolution of predatory lenders and universities whose business existence depends on this type of debt, then so be it. It's time to adapt or go extinct, Jack."
The problem is the courts would just knock it down right away. Biden could try to ignore the courts, using their own definition of immunity, but it would absolutely precipitate a Constitutional Crisis.
They didn't declare the President king. They stated official acts are effectively immune and left a gaping hole in the definition of what constitutes "official", likely leaving individual assessment to the courts which can be appealed right up to SCOTUS.