That's what these (alleged) "super heroes" really are... idealized, ubermensch-esque metaphors for the actual power wielded by the rich and privileged.
In fact, I'd say that Batman is the ultimate Objectivist wet dream - he perfectly personifies the fascist (as Batman) and the capitalist (as Bruce Wayne) in one person. Even Ayn Rand's creepazoid ancap sugar-daddy "heroes" didn't manage that.
I would like you to explain how Captain America and Superman are reactionary.
Captain America is an artificial warrior created by a Jewish scientist to fight the Nazis, and Superman is a baby sent away in a basket to be raised by not-dead parents who chose to use his privilege to help people.
Zack Snyder is an Objectivist and that's why his Superman movies stink. He doesn't understand the core themes of superheroes, he only understands the spectacle and surface theatrics.
I would like you to explain how Captain America and Superman are reactionary.
I mean... c'mon. Captain America is low-hanging fruit - the correlation between Captain America and actual US behavior in the world essentially writes itself.
Superman is a far more sophisticated representation of US-style liberalism - but, just like liberalism itself, that doesn't make Super Cheese any less of a reactionary.
However... we can talk about the individual politics of these characters all day long - and we'd be missing the entire point of the metaphor in it's entirety.
The problem with the "super hero" genre is not the individual politics of the characters concerned - it's with how they normalize and justify the concentration of power in the hands of these exalted individuals.
In other words - the problem is fundamental.
He doesn’t understand the core themes of superheroes,
Okay do fucking Spider-Man and tell me how "with great power comes great responsibility" is Objectivist. Rand wanted all the talented people to fuck off and leave the stupid poors to die! Spider-Man's first arc is realising that his powers shouldn't be used for self enrichment.
If you actually read the early comics, it takes Peter a good long while to learn that lesson and he still forgot it pretty frequently. Still, his journey toward learning that lesson was a core part of his character until the writers decided to just make him a flawless Mary-Sue.
I don't think the writers have made him perfect. His most recent movie, No Way Home, is about Peter trying to use superpowers to help his friends get out of trouble. Which backfires and causes a bunch of problems, and Aunt May dies saying "with great power there must also come great responsibility." Seems like a pretty on-theme story.