I actually think there's three reasons for Hollywood's preference for unrealistic action movies, none of which are directly tied to the other stuff, but the second and third factors may be influenced by it.
- Special effects and CGI are becoming better and cheaper relative to movies' budgets, making these kinds of movies relatively cheaper to produce.
- Going to a movie theatre sucks. It's expensive, the snacks are expensive unless you smuggle in your own, and you have to sit in uncomfortable chairs and don't have the option of pausing and rewinding. For the most part, it makes sense to wait for a movie to come out on Netflix and watch it then. However some stuff is simply made for the big screen. I have only seen two movies in a theatre in my adult life. One was a foreign film at an arthouse theatre with an exchange student we were hosting. The other was Avatar. It's a dumb movie, but it has great visuals, and seeing it in 3D in an IMAX theatre was absolutely incredible.
- A movie, running 90-150 minutes, is not a great format to tell an interesting story. Meanwhile, television is experiencing a golden age, and a miniseries or full-blown series is a better way to tell stories with plot twists and character development. So anything that relies on storytelling more than visuals makes more sense as a TV show.
Since my generation has less money to spend on things like movie tickets and is comfortable with watching stuff on Netflix, and likely has more free time due to being unemployed/not having kids, it makes sense to prefer things with a plot in TV form to movie form.
Of course, this still doesn't explain why a large number of TV shows are also escapist fantasies. And there, I think "the real world feels like it kind of sucks" for us does play a role. I'm trying to think of realist TV shows I like, and the first two examples I came up with
Bojack Horseman and
Crazy-Ex Girlfriend. Aside from fact that one involves talking animals and one involves people expressing their feelings through song, both are shows about mental illness. Now, I do watch shows where nothing technically impossible in real life happens, but the weird thing is that they feel less realistic than those two shows.