They used to make movies like House of Gucci every year, like clockwork, back in the day—glossy melodramas about rich and powerful people behaving badly and having lots of sex. Usually they were thinly disguised fictionalizations of extraordinarily well-known people, drawn from the trashy novels by Harold Robbins and Jacqueline Susann that dominated drugstore paperback racks. These books and movies generated contempt and disgust from middlebrow critics and sighs of lubricious delight from readers and filmgoers. Then Dallas and Dynasty hit the television airwaves and turned this adult guilty pleasure form into something the whole family could enjoy. And so the roman-à-clef melodrama became passé.
That's why the first half hour of House of Gucci is such a thrilling delight. It's got everything—a...