You know universal coverage exists, right? Europe, Japan, Australia, New Zealand... you can't claim it's impossible to structure when there are dozens of functional examples out there.

"Universal coverage" is not "we pay for everything without question or approval process". In both systems, there are people who decide what's covered, and for whom. As for "exploding costs", the US is more expensive - in both public and private spending - than the "universal coverage" spots. https://data.oecd.org/healthres/health-spending.htm