Always mildly annoyed by this type of meme.
First and foremost: Gotham is fucked. Like... really fucked. Evil secret societies run the place, the water supply is very likely poisoned in various ways, both conventionally and naturally, there's ancient evils buried under the city that have been corrupting it for centuries, a portal to hell in the asylum. We can say "Oh surely a food bank would help" and Wayne absolutely does do that via foundations in both of his parents names.... but all the shit to erase systemic poverty in the world can exist and The Joker, Zsasz, Mr. Pyg, The Court of Owls, Solomon Grundy, and the like are still going to be doing their shit (Not to mention big alien threats like Darkseid.). Likely most of his villains would still be on their grind except maybe Mr. Freeze who actually could have his problems solved by money.
Secondly: You gotta suspend disbelief. Make Superman a transitional power source and no one is gonna read it anymore, even if it would be 'realistic'. Any number of heroes could readily solve a number of the worlds issues. Why doesn't Iron Man put Arc reactors everywhere to power the world on clean energy? How come Storm doesn't get rid of every hurricane before it starts? Why doesn't Ice Man freeze up the poles and cool the planet down? The Flash could instantly deliver supplies to places in need. It's realistic, but it's boring, and boring doesn't sell comics. Okay, maybe Ruins but that couldn't be like... a whole series.
