Maybe it’s time for the MCU to end

I’m sure Marvell will manage the odd hit but the characters they’ll be rolling out in phase 2 don’t have near the appeal or, I’d think, drawing power of the original band. If they experience a string of box office bombs the execs will probably panic and fall back on rebooting the original characters with new actors.

That's why I suspect that by the end of Phase 4's crazy multiverse shenanigans they'll reset the MCU and we'll get the main characters again but with different actors and maybe some gender swapping !

The comics did that when they ran out of ideas and killed off some major characters that the fans loved.

Of course there is always franchise fatigue where people will just be bored of it and want something entirely new and that happened to Star Trek in early 2000s.

No one was interested in Iron Man, Thor, Captain America, Guardians of the Galaxy, Captain Marvel, Dr. Strange, and all the other C- and D-list characters around whom they built the first set of films. The magic is not in the characters, it's in how they are implemented. If you can't see that, look at what Sony did with Spider-Man compared to what he became in the MCU. And if you want a staggering example of how little characters matter, look at what DC's doing. They have arguably the two most famous heroes on the planet in Superman and Batman, and are churning out unmitigated shit that is ridicules far and wide.

What anyone thinks of a character going into a film is meaningless. The quality of the film is what determines the outcome. To this point, Marvel is 27 for 27 in creating films and shows that are acclaimed by both critics and audience.