i have no actual knowledge of the comics
i assume superman is the strongest most best unbeatable dude
so most plots are:
1. make superman weak thanks to his anti-sue green stuff
2. create bigger mary sue to job for him
this is because for brainlets a narrative 'conflict' must be a confrontation, and comic book consumers are turbo brainlets, moviegoers are turbo brainlets and so comic book movies are the intellectual equivalent of a supernova>end inb4
back on track:
take for example your premise of how strange a not-flattened city would be. now we put that in play. superman's enemies do not need to be stronger than him, if we realize that a conflict for superman isn't "will superman beat this jobber" (we know he will, well maybe excluding those trapped in the ensuing black hole of turbo brainlet gravity), but instead "how can superman beat this jobber without causing harm to innocents"
ah, now we are actually in the realm of what might be considered intellectually stimulating.
but this doesn't occur to you, because you don't actually take anything you see in a movie seriously.
this is why comic book movies are not, and never will be art. they are only entertainment.>And being in a city raises the stakes a lot more than if they were just out fighting in a cornfield somewhere
yup. you're right. there's no other alternative. settings are wholly to 'raise the stakes.' you don't even see settings and the background of humanity as anything other than static white noise. how depressing.