That's a specious argument. Not many people wanted to see Iron Man or Thor or Star-Lord, or had even heard of them, until their movies turned out to be really good and made people want to see them. It's getting it completely backward to say that a movie's or show's success depends on prior interest in the characters. Good movies and shows create that interest. That's why Star Wars, featuring characters nobody in 1977 had ever heard of before, was a smash hit spawning endless sequels, while 1980's Flash Gordon, based on a character who'd been a household name for nearly half a century and was Lucas's inspiration for Star Wars, earned about 1/8 as much at the box office and was getting pulled from theaters after a few weeks in an era when films tended to stay in release for months.
There was a lot of interest in Iron Man and Thor at least, prior to their movies' releasing. Star-Lord yeah, I'll give you that.
After Iron-Man 2 fans also wanted a solo BW movie. But they got that after they killed off her character.
And I find it highly... selective... that your list of characters "not many people wanted" consists exclusively of women and people of color.
Yup. They do. Now tell me: where were the people of color for the Eternals "This movie is gonna save lives!" movie?
Did a bunch of south-east Asians flock to The Marvels because it had Pakistani representation? Nope. It is Marvel's biggest flop.
Where is She-Hulk 2nd season? Why did Marvel delay Iron Heart for two whole years after spending 150M on it?
Oh, yeah, what about Secret Invasion? That was headlined by the great Samuel L. Jackson. Why'd nobody watch it?
Armor Wars? People wanted
that. They bungled it hard, first as a TV show, then as a movie, then scrapped it.
Not my fault that Marvel themselves gave the ladies and people of color horrible fucking movies and tanked their good will.
"Not many people wanted" = these characters were not as famous so wasn't in the public consciousness as much, but Marvel
used to have the ability to make them household names.
But somehow they lost that ability.
They could make Groot a big fucking name, but made horrible tv shows out of Ms Marvel and She-Hulk, giving more ammo to the actual racists and sexists online.
And currently, look at the Blade fiasco.
Everyone wanted a new Blade after Endgame, even got a teaser with Maherharshalabaz Ali in Eternals.
Where'd that go?
Absolutely dropped the fucking ball after having a two fucking time Oscar winner wanting to inhabit that character.
They spent over a billion dollars making every other movie and tv shows nobody watched, but not Blade.
That, is Marvel fatigue.