Having worked for 20+ years at a world famous hospital I can comment on this point.This nations finest hospitals...hospitals in Boston,New Haven,NYC,Baltimore,San Francisco,etc....are,it can be said,self contained medical "meccas".For example...if you walk into the ER of,let's say,Yale New Haven Hospital with chest pain the fact that you don't know anyone there will not prevent you from getting just about the finest care available on earth regardless of how serious or how rare your problem is.In hospitals like that,and hospitals like Mount Sinai,every single medical specialty is *very* well represented.It's when you get away from these "mega hospitals" that problems of quality of care (and other problems) might arise.
But if I moved down the block from New Haven, and had to go to a different hospital that was closer, then I would still get terrific care, but how would it be paid for if I was insured at New Haven?
And that's an important point you make about what I affectionately refer to as "flyover country"...there are a couple "mega-hospital" systems where I live, that seem intent on swallowing up every other small hospital system around (it's unpleasant to watch!), and, more to the point, there are many people in rural Ohio areas that have various options now (they are going to have to travel either way) that they may lose if, say, Cleveland Clinic just takes over Ohio. Something about that idea makes me very uncomfortable!
It's a smaller market here, and one, two, or three mega-hospital systems could easily cover everyone in the state...
Perhaps I'm being paranoid? lol! I do not like the Cleveland Clinic, so maybe I'm just biased, but if you have to get your insurance from your hospital, it wouldn't work to have all these smaller local hospitals everywhere, and we're seeing that already with the Clinic's continual localized take-overs, buy-outs and expansions...