I always wonder how Americans feel about their entertainment largely being set in American with Americans speaking American accents. How can you imagine a different world?
There is a lot of regional variation, but the difference is quite a lot smaller than in other places in the world.
It is indeed harder to imagine a different world because we are culturally isolated, but our isolated world is quite a bit larger than I would bet would be easily imagined coming from somewhere else.
"The Book of General Ignorance" talks about an example of this with frogs:
> There are 4,360 known species of frog, but only one of them goes "ribbit." Each species has its own unique call. The reason everyone thinks all frogs go "ribbit" is that "ribbit" is the distinctive call of the Pacific tree frog (Hyla regilla). This is the frog that lives in Hollywood.
> Recorded locally, it has been plastered all over the movies for decades to enhance the atmosphere of anywhere from the Everglades to Vietnamese jungles.
Frogs don't sound like that here but that's not something that ever seemed incongruous to me until it was pointed out in a book.
The most stark contrast I’ve seen is in the indie film Lady Bird where (SPOILERS) there is a setting change from a very small rural American town for most of the plot to New York City at the end of the film, with it’s subways, density, and architecture that felt familiar to any watcher from an urban area.
Similarly, the suburban Texas setting of the King of the Hill deliberately contrasts itself with New York-based shows (referring to Seinfeld as, “I'll tell you what, man, them dang ol' New York boys. Just a show about nothin,’” with other joked about the disdain of many Texans of New Yorkers).
However, I remember the depiction of Sacramento in the movie was intended to stand in contrast with a bigger city (which is why a major conflict is about the protagonist wanting to move away).
Reviews by several critics also described that setting as a small town, and I remember reading discussions around the release about how other perspectives of Sacramento could view the place as much larger and diverse.
The film’s writer and director Greta Gerwig more precisely described her view in an SF Chronicle article (https://www.sfchronicle.com/movies/article/On-location-How-L...): “It’s not rural, but it is not like a New York or a San Francisco either. It is somewhere in the middle.”
America as shown by Hollywood is a different world.