Dissenters have been loud. In 2019, Martin Scorsese pronounced Marvel movies “not cinema,” earning the undying enmity of comics fans. Last year, Quentin Tarantino lamented Marvel’s “choke hold” on Hollywood and said, “You have to be a hired hand to do those things.”

Collectively, the M.C.U. movies—the thirty-second, “Guardians of the Galaxy Vol. 3,” opened in May—have grossed more than twenty-nine billion dollars, making the franchise the most successful in entertainment history.