Not a movie but The Boys is a show that largely follows a regular guy impacted by the fallout of living in a world with superpowered people. Solid show though!

Also The Watchmen show and movie are mostly regular people with no actual powers. The show is excellent, the movie is pretty decent.

There's other stuff out there (Agents of Shield, Gotham, Arrow, etc.), but most of it is not nearly as good as the above two shows IMO.

Extraordinary, was a British show about the only girl that didn't get a superpower, in a world where everyone does.

Does Agent Carter count? I don't think she's a superhero?

I’d say that the show Gotham is primarily about Jim Gordon and an adolescent Bruce Wayne dealing with all of the supervillains in Gotham City, but, drama queens that they all are, the show is a lot about them too

Marves Agents of Shield? Season 1 specifically. Season 2 and on goes into metahuman territory

Powerless is about unpowered characters in a super hero universe.

There was a show called powerless. It was about employees at Wayne enterprises. It was a comedy. It didn’t last long.

The Boys ?

Would The Penguin count?

Breaking Bad actually happens in the Marvel universe. They just don't mention any of it because they are busy selling drugs and such.

Encanto.

You might check out Free Guy. It's about a video game NPC who comes to life in a Grand Theft Auto themed universe.

Mystery Men is all about the B-Team superheroes who have to step up after Captain Amazing, super hero of Champion City, releases Casanova Frankenstein from the insane asylum in order to get better ratings and sponsorships but instead gets kidnapped and accidentally psycho-frakulated. Their powers are: get mad, throw forks, fart, bowling ball, shovel, and invisible when nobody is looking. Doug Jones shows up as Pencilhead and Dane Cook as The Waffler during tryouts. Tom Waits also shows up as basically Tom Waits.

There was a TV show about Batman’s butler.

Agents of Shield was about Shield: The Marvel universe non-superhero government agency made to... Uh... Keep superheroes in check? I don't even remember, lol.

But they're just regular ass people who are badasses without super powers.

Oh I have an old one: Norman Normal.
It's about a guy who's the only one in the family not developing super abilities.

Wonder Man has powers, but we see very little of them. It's mostly about a persecuted minority trying to get work as an actor. Ben Kingsley is fantastic in the show.

Andor, depending on whether you consider Jedi superheroes.

Interior China town is tangentially related. Not super hero world but procedural police show world and it follows people not part of the cast

Since Batman has been mentioned a bunch, you may like a twist on his formula. In the Absolute Batman comics, Bruce Wayne isn’t rich at all - and engineered some of his gadgets off his job at a construction site. But The Joker? Obscenely rich.

Monty Python's Life of Brian is the first one that came to mind

The two Joaquin Phoenix Joker movies, maybe kinda sorta? No flying or capes or utility belts, but they're about Batman characters, and presumably set in a Batman universe, or at least a precursor/adjacent universe.

Gotham Central and Ordinary are a couple good graphic novels that explore this idea.

Marvels for sure if you're into reading comics.

Not a movie, but the song Jimmy Olsen Blues by the Spin Doctors seems on point.