Alternatively, go try it. You could take a paycut to go live in bumblefuck any time. Why not today? I think you'll discover pretty quickly that the grass isn't that green over there. They are low rent because there is either nothing to do, or because they're dangerous.
Most such people have never seen inland states from ground level.
I'm a CA native looking to leave, and Nashville is one possible landing zone that is getting better and better press (outside of conventional media, which here retains the coastal bias).
Yeah, you don't know anything about Nashville.
I'm considering BOS->ATL right now, because Atlanta is also a really nice city but a little more tech-friendly.
There is a large fundamental difference between Outerbumbelch, North Dakota and Dallas, Kansas City or even Denver.
This country is full of low-rent places. If you don't like your rent you don't have to stay in the city. What people want is to be somewhere desirable but not have to pay a premium for being someplace desirable.
That happens briefly when you find a good place that nobody discovered yet. But it never lasts. Eventually people find out. My property taxes have gone up 3 times in 5 years for precisely that reason. It's a small price to pay, IME, to be somewhere you like even if you have to pay extra.
That's a few things off the the top of my head. Now some downsides: 1) Culture (art, music, etc) are generally less available. 2) There aren't as many conveniences. 3) You pretty much have to drive everywhere in rural areas. 4) Towns aren't very well planned, I rarely see any bike lanes or pedestrian oriented areas.
I also don't think it's totally fair to compare it to the plains states, those places are emptying out for a reason (ok, several reasons).