Of possible interest, my wife does not like vivid sex portrayed in movies because she does not think it adds the right kind of substance to the story, and frequently is used as a crutch, there mostly to titillate male brains. No she’s not a prude.

I agree about the latter and male brains, at least my brain.

I have alway enjoyed it, and my position is that if as the audience, you are voyeurs into these character lives, it feels like a more realistically portrayed story, vs a PG feel, when the camera averts your eyes, or closes the door every time there is intimacy.
Yet this falls far short of porn for a good reason. For a legitimately seriously story to be portrayed imo, it has to stop at R rated sex. Once you exceed this limitation imo, the story is diminished and the sex becomes primary. If one needs sex to be primary, dial up some porn.