I'll argue that stuff like Iron Man was genuinely good, it was proper storytelling, well-cast, well-written, well-directed as were many of the early films. They should have called an end to proceedings with Infinity War. Now it's AI-written, poorly directed, with no character development (compare Iron Man, Captain America etc. with Captain Marvel, who basically started the movie as she ended it, minus a pair of gloves).
The first Iron Man was great. I quite liked Captain Marvel too. And Thor Ragnarok. Infinity War is dreadful.
Superhero films work best as standalones. Trying to tie them all together into a coherent universe is essentially where they went wrong.
I think that's true. Pretty much the only interesting stories of superheroes are the origin stories. Hero's journey, and all that. What the hero did next isn't so compelling, because you already know they're a hero. See also: Endless police procedural dramas based around the 'maverick' investigator, whodunnits generally, Star Wars* etc.
I stuck with Marvel as far as the end of the infinity war stuff. The Tony Stark storyline, if you like, from origin to death. It kind of made sense. As I think I may have said before, when I went to see Iron Man, I was not a Marvel fan, nor immersed in the world of comics - 2000AD† being the exception, but that was in the 1980's when that dystopia was the future possibility rather than the lived present. As an antidote to the more-or-less contemporary DC stuff (Dark Knight, Superman Returns) it was pretty good, I thought, and obviously came from a different mindset. The later films, not so much, and the last one I saw (Dr Strange in the Cash Generator, I think it was called) was just pants.
*The original Star Wars (1977) film was a hero's journey origin story which borrowed from Dune, thereby missing both the better plot, and the point. I still like that one, and the recent Dune.
†Speaking of 2000AD, I still think the Karl Urban Dredd film was far better than most of the Marvel stuff, even if it was a thinly disguised version of The Raid.
Tony Stark was great, and along with the other early characters, they followed an arc that came to a natural conclusion. Unfortunately, the movies kept going and they've never replicated the original storytelling, probably because the movies are just product now.
Captain Marvel was vaguely amusing, but that was that, her character never progressed, nothing was learned or earned. The curse of later characters, who became identikit superheroes fighting identikit villains in an identikit plot. There were a few brief reprises like
Ragnorok (not close to replicated in the terrible
Love & Thunder) and GotG, which thrives on a great cast. The last couple were a deluge of surprisingly poor (given the budget) CGI and increasingly tiresome, off-tone one-liners, and some questionable morality (Wanda, for instance, basically enslaved an entire town, but apparently that was all ok). Perhaps the stories weren't written by AI, though that option may offer a path to improvement. Take it from me,
Secret Invasion was probably one of the worst series ever made, and I only say one of the worst, because I watched half an episode of
She-Hulk. I have had more enjoyable episodes of diarrhoea.
