It’s probably with noting that Brad Bird is an admitted Objectivist, and that’s been a theme in a slew of his films (even his Mission: Impossible entry).
My honest opinion on this is that superheroes (existing superheroes, anyway) exist as many things to many people. Superman was created by Jewish writers, at the height of WWII and the Holocaust - to them, he represents the goodness of power, an antithesis to the German “Übermensch” who uses his considerable strength for protection and aid. Batman was created as a stalking, dark detective - not a hero as much as a horrible caped vigilante, capable, for better or ill, of using tactics no lawful detective ever could. He brandished a rifle and employed lethal scare tactics in hunting foes as if prey.
And over eight decades and change, these characters have been warped and changed by authors and artists and public perception and adaptation, to the point that you can find canonical evidence to prove pretty much anything you want about Superman, or Batman, or Wonder Woman. The concept of “superhero” as a whole can only be defined personally, as the fictional examples we have are numerous, varied, and self-contradicting in ways that there’s no “one” definition - even of individual characters!
So it’s especially relevant to me that the politics of The Incredibles are Randian, because director Brad Bird abides by Randian principles. It also hurts me to read “you can’t have a hero who rallies against the status quo,” because as long as there exist superhero authors who rally against the status quo, their heroes will, too. Kamala Khan wouldn’t exist if G. Willow Wilson wasn’t angry at representation of Muslims in comic books. She wouldn’t be so embraced within the fiction if her character didn’t share some of that anger. I can probably list hundreds of examples of superheroes whose job it is to call out both the methodology and ideology of other superheroes.
Hell, there was a whole mainstream movie about this very concept - in Captain America: The Winter Soldier, the key conflict was between Captain America and S.H.I.E.L.D., because they “protect the world as it is, not as we’d like it to be”. And, of course, S.H.I.E.L.D. was revealed to be corrupted by Hydra - the MCU’s stand-in for Nazis - making Captain America’s worry that the status quo was toxic even more justified.
…I’ve already said a lot, but the other angle I have on this is that not all superheroes are written as role models. Not every author has written Batman to be a good man, or a noble man. Tony Stark, as Iron Man, has a popular story called Demon in a Bottle, about his struggles with alcoholism. Peter Parker infamously made deals with (one iteration of) the devil, Mephisto, which isn’t typically associated with rationality. Villains, especially recently, have become allies, or tragic figures - they gain new motivation, with justifiable outrage that paints the titular heroes in shades of moral ambiguity - or as outright monsters. Heroes turn on each other, betray each other. And frankly, superheroes can, have, and should be portrayed as deeply flawed, as wrong, and they will learn and change and, as their authors have, as their publishers have, as their readers have, adapt and evolve and become what is wanted and needed of them. It keeps them both more real and more interesting - and, importantly, more relevant. Watchmen wasn’t written because Alan Moore thought heroes could be better, it was written because he was confident they couldn’t.
And this only really covers “mainstream” superhero - those appearing in family films, in animation, in comic books published by Marvel and DC. By the time you get to Spawn, or to Judge Dredd, the aim of the fiction changes considerably - be it satire, or counter-culture, or introspection. I’ve seen people call Hellboy a superhero. Whether intended to be or not, I think that says a lot about how we make personal connections to the concept - Hellboy is an absolute outsider, who rejects pretty much every establishment of the status quo by merely existing.