Yup. Hence why we went from too much patriotism post-9/11 to too dark after Nolan Batman to too quippy after the Marvel takeover.

I remember first watching The Avengers and finding it refreshing. "This is fun! Why aren't more action movies fun? They're always so gritty and violent and serious, even though the protagonists are functionally superhuman, they're always so mean-spirited and the dialogue is is always so aggressively masculine and primitive and angry." And then that was everything for the next few decades.

Not quite. It’ll first be masticated, digested, and excreted before a simplistic version of it becomes the next mainstream.

Perhaps a more accurate (and less cruel) analogy would be that it will receive some scaffolding to sustain it - the leading edge is always unfinished. By the time it becomes mainstream, it’s closer to a product than an idea.