Think life-threatening non-emergencies.

If travel is necessary for medical treatment, it ought to be covered by insurance, so the price shouldn't matter. Medevac flights, aka air ambulances, are a thing.

"covered by insurance" doesn't mean much if you're still billed $10k or more after insurance.

My father has decent insurance as a retiree and still got billed for an ambulance ride after he had complications following a jaw surgery.

I've seen a bunch of anecdotal stories about how it's cheaper for someone on the west coast to fly to Korea, or down to Mexico, for non-critical surgeries, spend a week recovering, and then fly home.

I think it's a fair assumption that the US healthcare system would have been overhauled long before the complete elimination of the competitive market for commercial air travel, which is what this thread is about.