It's not just since then, that's just when you noticed it.

It's the pursuit of mass appeal, as studios consolidate there's less competition for different demographics or preferences. Everything aims for a global phenoma that could kick off decades long franchises.

So we end up with "safe". If any significant demographic wouldn't like something, it's cut. If any significant demo needs something to draw their views, it's added.

So we get an occasional show that feels ok.

But it'll never ever hit as hard as something that was dialed into your specific demo like what used to be the norm. No one wants to make the best "sci fi" or "vampire" show, they want to make the best "show" period. Something that everyone will watch and no one will hate.

It can easily be fixed by breaking out the corporations so they have to compete and don't have the resources to go for global blockbusters like Star Wars or Harry Potter.

People would just make the best movie/show they could to tell the story they wanted. And hope enough people identify with it to make something else next.