You're right. In a lot of cases, people don't understand the difference between a story that can be told in one shot and a story that needs to go on longer. You see it happen with novels when the story was clearly done in one book but the author decides to stretch it for 15 books. You also see it when people complain about book to movie adaptations - you NEED 27+ hours to explore every single aspect of the story, including the character development and connections. *It's this reason that if Twilight actually does get adapted for TV, I will watch it. We could finally get elements of the Twilight fanon added to the story.
But in the case of superheroes, while I agree that superhero work is better in TV form like shows like Arrow, Flash, and the Boys, I think people are tired for superhero stuff is because they don't mean anything. When I was a kid and the X-Men movies came out, one of the first things I learned was that it was a metaphor for the Civil Rights Movement. Spiderman gave us "with great power comes great responsibility". Early Iron Man gave us a story about growth and redemption.
There is a great TV show from the mid 2010s that explores superpowers as a type of disability. The work stuck with me because the characters all paid a price for existing with superpowers. They weren't trying to be vigilante superheroes - they were just trying to live. A MG book series that I love explores superpowers as a metaphor for you developing talents, self-control, and accepting yourself as you are.
But you don't get that anymore. Superhero women singularly fight the "patriarchy" and often only have to deal with "accepting themselves". And male heroes are being phased out for the sake of empowerment. We don't want a neverending series of sequels and recycled plots. We want stories to mean something.