I think that Captain America, Thor, and Hulk are kind of overrated. I think that the Thunderbolts* are underrated.
Batman has become the most overrated hero ever. He was best when he was a patrolling detective/martial artist. He has a suit he can use to fight Superman, but goes on patrol and has trouble with the Riddler. I like Batman, but his fandom is ridiculous. Underrated: Colossus. before there was Worf-Syndrome there was Colossus-Syndrome. We have a new threat, and to show how tough the threat is we shall have him punch out Colossus. He is athletic and has super-strength. He could go on patrol easier than Spider-Man.
Toad is overrated. When he gets struck by lightning the same thing happens to him that happens to everything else. That’s not very super.
Captain Carter is cool but not so cool that What If dropping it’s premise to become her show was a good idea. Overrated.
Overrated: Iron Man - He was a B-list hero before the MCU. Any of the rest of the Avengers should be able to school the rich kid at any time. Underrated: Hulk - too often played for jokes anymore. The power he has can only be rivaled by the horror his unchecked rage could inflict. Perhaps the truly underrated hero is not so much Hulk as Bruce himself. His self-control, meticulous study, and unselfish heart makes what otherwise could be a deadly weapon of evil, into a champion of heroes. He knows how to channel the beast within.
Overrated: Stoner Slob Improv MCU Thor (RAGNAROK and after) Underrated: Faux-Shakespearean early MCU Thor (everything pre-RAGNAROK)