One of the most charming elements of the superhero story, for me, lies in the fact that the world it all happens in is our world - that this fantastic, furious, cosmic stuff happens in what could be the skies over our heads - and sure, it should turn the world into something unrecognizable, but it doesn't.
This is, to be fair, an existing subgenre in action-adventure serials. But typically, when they do stories where the hero is completely helpless the hero is impotent in the face of real-world horrors like famine or cancer or 9/11 (superhero comics, in particular, had a brief period where everybody did astonishingly bad pieces about how superheroes couldn’t stop 9/11). This subgenre amounts to mawkish glurge in which the fact that stories are fiction is treated as a flaw, and anybody who writes it should be punched. (Note: This proposal would likely prove fatal to J. Michael Straczynski.)
"John McClane's once-relatable, everyman hero now makes no sense. According to this movie he's still just an NYPD detective after all four movies. HOW? Yeah, they keep telling us he's tough to work with every other day, but now he's saved Los Angeles, Washington, New York, and the entire country. And everyone knows about it! Why isn't this guy running the Department of Homeland Security? Or a private security firm? Or just write a book and retire rich as hell?"
The more you look at Tony Stark, the more you realize he developed the mini arc reactor only to play God, or at least a shitfaced version of Shaquille O'Neal's Steel. Case in point: After first discovering this world changing energy source, he makes exactly one more arc reactor, and uses it to power his pizza-colored murder suit. He doesn't make any demonstration models for his company. Hell, he doesn't even draw up any blueprints. In fact, he's so damn Howard Hughes about the whole operation, that he instructs Pepper Potts to destroy the original model, rather than turn it over to his company's engineers to mass produce and solve all of the world's resource problems forever.
Sue: Who else would have the world's coolest PDA? You going to put it on the market?
Reed: I can't. Sony paid me three million not to.
As a side note, those superheroes who develop or invent entirely unique powers, and then hoard them? Screw those guys. When Edison invented the incandescent lightbulb, did he keep its secret to himself, and then bust nocturnal crime as the Illuminator? Fighting the nefarious Doktor Lightning with the help of the Amazing Flight Brothers? No. Because, as a man of Science, he was familiar with Newton's statement about the shoulders of giants.
The greater the problem, the faster he could solve it. He’d taken the time one afternoon to solve world hunger. Six hours and twenty-six minutes with the internet and a phone on hand, and he’d been able to wrap his head around the key elements of the problem. He’d drafted a document in the nine hours that followed, doing little more than typing and tracking down exact numbers. A hundred and fifty pages, formatted and clear, detailing who would need to do what, and the costs therein.
It had been bare bones, with room for further documents detailing the specifics, but the basic ideas were there. Simple, measured, undeniable. Every major country and ruler had been accounted for, in terms of the approaches necessary to get them on board, given their particular natures and the political climate of their area. Production, distribution, finance and logistics, all sketched out and outlined in clear, simple language. Eighteen years, three point one trillion dollars. Not so much money that it was impossible. A great many moderate sacrifices from a number of people.
Even when he’d handed over the binder with the sum total of his work, his employer had been more concerned with the fact that he’d shown up late to work for his job. His boss had barely looked at the binder before calling it impossible, then demanded Accord return to work.
While it may strain credulity, one of the accepted tropes or conventions of the superhero genre is that the world not be changed by the presence of the supernatural, supernormal and supertechnological heroes. (I would argue that Watchmen by Alan Moore is arguably science fiction, not superhero fiction, because it sets aside that convention, and dares to have the world change.)
The world defended by the Justice League of America or the Teen Titans has extraterrestrials, Amazons, mindreaders, witches, cyborgs, and reincarnated Egyptian princes with antigravity wings, but none of these inventions, discoveries, or fantastic elements has any effect on the world outside (except perhaps for a secret military, espionage or police teams using futuristic weapons).