It is the closest healthcare system in the developed world to free market capitalism since every other country has socialized medicine; a system much more free-market than ours would create an untenable hellscape for the vast majority of the population that would be voted into oblivion or cause massive riots and death. We sit at the most extreme free-market end of possible healthcare systems that could feasibly exist in reality.
Imagine a true free market healthcare system. Or just one step further than ours: no medicare. Imagine if every middle-aged middle or lower class American had to, as their parents age and require more healthcare than anyone can feasibly afford, choose: bankruptcy and permanent insurmountable debt, or watch your parents die knowing you chose not to stop it. What glorious freedom.