Except, airplanes kinda do flap their "wings" - each motor blade is a wing. The motors then turn those blades - i.e. flap the blade wings, for the same purpose

Except, airplanes kinda do flap their "wings" - each motor blade is a wing. The motors then turn those blades - i.e. flap the blade wings, for the same purpose - push air and generate lift. Airplanes also have an additional set of wings for gliding.