There are many manufacturers that sell all kinds of vehicles in the USA. Some made completely abroad from various different countries. Some domestically. And a lot are a complex mixture of the two. But you think there is a grand conspiracy/collusion among them all of them to deprive consumers of lower-priced/lower-end models?
The big 3, which have American brand loyalty up the wazoo, realized in the 90s they made more money on bigger vehicles. They they've been marketing bigger and bigger vehicles to Americans. It's why the F-150 is the best-selling pickup truck (and how much larger it is now than in the past). Heck, for a few years in the mid 2000's, F-150's were sold with so much luxury they had no cargo carrying capacity once you loaded it up with a couple of adults - you had maybe 150 lbs of axle weight left.
It's also why SUVs are insanely popular, and not cheap small SUVs like the foreign makes, but the big ones.
It's why the Big 3 have been getting rid of less profitable sedans - they're marketing people to buy big cars. And the cars they do make in the lower end of the spectrum just can't compete - with major recalls going on.
The only reason America still makes cars are EVs like Tesla. The ICE cars are almost all foreign makes.
The Big 3 aren't worried about Toyota Camrys or Corollas because Americans are loyal to the Ford, GM and Chrysler marks. It would take a seismic shift to get them to consider a Honda or Toyota. And even more to go with a Hyundai or Kia. All of whom make low end vehicles that are cheap but relatively full featured.
Ford isn't going to sell F-150s to Japan - too big, too expensive, not very useful. But Ford doesn't care about the Japanese market. Toyota and Honda, meanwhile, sell very nice efficient cars to Americans to fill the lower end gap. Of course, Trump also goes around and does tariffs, but a lot of those are made in the US to be sold in the US.
But brand loyalty is a fierce thing, especially in red country.