I'm sorry, what?

Peter Parker being seen as a nerd when out of his suit is one of the defining characteristics of Spider-Man.

Their intelligence the defining characteristic of Richards and Stark (also his money in the latter case, but he's lost that on occasion without that making him not be Iron Man, in fact the one time he did stop being Iron Man was because his alcoholism was making him too irrational).

Banner's intelligence is almost always a necessary counterpoint to Hulk's brutishness.

Going to DC, Batman's main asset is arguably his intelligence. Sure, he's a ninja, sure, he's a billionaire, sure, he's dark and scary. But take all that away and his intelligence will still allow him to keep fighting crime.

Speaking of Batman, I forgot about Daredevil; sure, again, he's a ninja with super-senses (except for sight), but we see a lot of him being a lawyer, and he sometimes wins in the court what he couldn't win by beating people up. Also dude won against fucking Mephisto, obviously not by beating him with his little sticks, but through sheer conviction. It took Doctor Victor Von fucking Doom decades to beat that devil. Matt fucking Murdock beat him in four issues by essentially turning the other cheek.

Side notes? Far from it. (In Richards' case, and arguably in Stark's most of the time, heroing is the side note; the Fantastic Four almost never go looking for it, rather stumbling upon it from time to time, and Stark spends most of his time looking after his company, not seeking crime to fight.)