>I’m no specialist on the US system, so could be wrong, but I heard from a friend who paid $4K cash for a broken ankle (arguably out of a total bill of $25K+, and not sure what type of healthcare they had), whereas your bill in the U.K., France or Spain for the same injury would be exactly zero (as an example, from countries I know better)

UK, yes. In France, aren't there copayments? I thought the French system typically covers 70% of hospital bills.