There are so many more interesting, surprising stories to be told that leave the viewer with unresolved things to think about and captivating cul-de-sacs along the way. The 1970s films were full of odd, interesting plots and films where it was unclear who the protagonist was (let alone a hero). Then Lucas discovered Campbell and made two pretty-good, unbelievably successful kids' films and modern cinema was born.
Now every film (especially kids' films) are a take on a James Bond plot whether they are about loveable zoo Creatures and cheeky penguins, toys in a nursery-school or talking cars: a super-villain, a secret base, a mysterious super-weapon… yawn
Grown-up films are no better: reduced to a sorry stream of infantilised garbage about super-heros who each in turn is given super-powers only to see them quickly taken away to provide some tension before a giant battle in which cities (and budgets) are destroyed for no good reason (accept perhaps to deliver a few half-decent one-liners) before a last-minute triumphant victory in a working steel-mill (if budget allows) or some disused warehouse if not.
sigh
Insofar as there is a Hollywood formula, it's more Save the Cat than Campbell (or even the Writer's Journey), and the former does not derive from the latter.
I used to know a screen writer, and he described Hollywood writing as a theme park ride you watch on a screen. There are standard scenes that every action movie is supposed to have, usually delivered in a standard order, sometimes with standard dialog. There are optional scenes from the Generic Hollywood Scene Library Sorted By Genre that writers can add as needed. The rest is CGI, costumes, and camera moves.
And it's this way because it's what the middle of the bell curve pays for. Anything too clever or original or interesting or challenging may win awards and/or critical praise, but it's not what The Average Movie Ticket Buyer wants.
To add: the original research is pretty much useless, as others have pointed out. That doesn't mean someone who actually understands the industry couldn't codify the tropes and cliches and produce a Plot and Character Machine that generated commercially valuable output. There are quite a few steps from that to generating a filmable script, but even a relatively simple outliner that hit the spot would have real value.