> But why - I still don't understand what is causing the problem in the US? Even in the non-US systems, somebody has to pay, so how can they afford it, given that all other countries are poorer than the US?

Perhaps the issue isn't that the US as a whole can't afford it, but more that medical treatments are expensive and the rich aren't willing to subsidise for the others.

In countries where it's funded essentially via sliding scale income tax, the rich don't have a choice but to subsidise it.