What movies do you suggest Marvel make instead?
Better superhero movies, I guess.
Which, it looks like they're starting to do. Marvel has always struggled to match memorable heroes with equally memorable villains and stories, but by all accounts, recent efforts like
Black Panther,
Thor: Ragnarok and
Spiderman: Homecoming are doing just that. Problem is, the way they've set up the MCU, as this big multi-film convergence, it means that you're not allowed to just pass over the less memorable entries, or even the ones that just don't interest you personally, because every three years it turns out that
Doctor Strange was going to be on the test after all. So you end up with this weird structure where you can't keep up with
Guardians of the Galaxy, a film which previously had only the loosest relationship to the rest of the MCU, without being expected to know why Bondledonk Cumberdink is doing a turn as metrosexual Gandalf, and that might turn out to be asking too much.
In fairness, this is assuming that
Infinity War actually has enough consequence for the MCU to justify it's grandeur, which the last two Avengers films didn't really manage. The only real consequence of
Age of Ultron was setting up
Civil War, which turned out to be a better Avengers film than either actual Avengers film, no necessary reason to think that
Infinity War will be much more impactful.