The US has some different existing dynamics that other countries don't have. We have a deeply entrenched fully private and profit-driven delivery system. We ended up with employer sponsored health insurance endemic in our society over a relatively short span of time - where other countries moved to UHC instead. We have a gordian knot in the US and we can't just cut it in half and be done with it, because there are a lot of negative consequences of that.
My preferred approach for the US specifically is to actually start with the delivery system and just nationalize that sucker. All doctors, nurses, clinicians, therapists, etc. would be salaried government employees (complete with federal benefits). Medical training would be government funded based on aptitude and ability to complete the coursework satisfactorily. Facilities would be government owned - and distributed in a way that allows access in less urban areas instead of the current health care deserts that we're dealing with. Drugs pricing would be negotiated federally.
I agree that nationalizing the entire healthcare delivery system might theoretically solve cost disparities, but achieving that politically is an enormous hurdle.
Universal coverage, specifically models like Medicare for All, already have substantial public understanding and some degree of support.
Medicare for All brings all patients into the system, replacing the current patchwork of private insurance, Medicaid, Medicare, and the uninsured who rely on expensive emergency care. By creating one integrated risk pool or regulated set of payers.
So If everyone is covered and there’s a single or harmonized set of rules and fee schedules, then subsequent changes, like altering how care is delivered, reorganizing hospital ownership, or integrating preventative services, become logistically simpler.
However, insurance companies often lobby politicians and use the media to frighten the public with claims of government inefficiency and brand such proposals as “socialist.” Consequently, meaningful reforms are unlikely to occur anytime soon in the land of the free and home of the brave. At least until enough Americans are fed up with being stupid.