America (disclaimer: I'm a US citizen, born and raised) has this delusion of rugged individualism, that everyone should pull them up by their bootstraps. In reality, everyone who is successful is simply taking advantage of those who came before them, and shared infrastructure (both the physical an economic types).

I don't see Americans adverse to Medicare, which is essentially single-payer for anyone over 65. Why does being under 65 mean you should die in the street without healthcare?

Single payer is cheaper/more efficient than our current system. We just need to find the political will to implement it, and cut the legs out from anyone attempting to stymie that change who is currently profiting from the status quo.