Lol, im sure its just a coicidence that you are parroting the GOP by calling on Biden to resign the presidency right now.
No, it would not strengthen her campaign if her running mate made the entirely unprecedented move of resigning in office for no stated reason. The procedural shitshow a GOP house would make the process would become the whole news cycle until the election.
She is a much, much stronger canidate in her current role, being able to brag about every Biden/Harris accomplishment and not have any baggage of an active presidency, especially one that would be assumed in a ginned up shit show by her politcal opponents.