The SCOTUS has ruled a sitting President can break any law s/he wishes provided the action is within Presidential duties.
Pardons are defined within the Constitution as a President’s prerogative.
Biden’s decision to pardon his son, while understandable, is not Justice, but there is absolutely nothing can be done about this example of un fettered Presidential power.
Biden’s habitual critics might measure their criticism of this act, it is certain to be followed by far more egregious uses of the President’s pardon by the incoming President.