Well, there are some rural staples like BBQ, and Mexican to a degree.

But, yes. The sort of ... enduring narrative is that rural areas and suburbs have chain restaurants, diners, and fast food, because immigrants go to cities and open restaurants from their native cuisine, and that suburbanites think black pepper is spicy and sushi is gross.

In actuality I think immigrants are increasingly (a) enamored of the American big-car / big-house lifestyle (makes sense, they choose to come here) and (b) bought-in to the notion that cities are dangerous, with bad schools. So immigrants rent a place in a strip mall near the suburban school district some other immigrant said was good online and start restaurants there. Google maps exists, suburbanites think nothing of a 25 minute drive, so they ask around online after the best examples of a particular ethnic cuisine, and they drive there.

In Maryland, where I live, it's certainly true that the highly-regarded Chinese and Korean dining is in suburbs. Latin Americans, specifically Guatemalans and Salvadorans, are the only immigrant group moving in to Baltimore (where I live) with any sort of enthusiasm.