Why should every country have the same solution to healthcare? The US was formed as a democracy when 'the rest of the world' was run by monarchs. Healthcare is still a rivalrous good, and if we don't limit it by who can afford it, we will limit by some other ambiguous term like 'need.' My friend's grandma (80 yrs old) just had to fly to the US from Paris to have a surgery for which the French system deemed her ineligible (she was too old).
Single-payer systems have a variety of implementations - Australia has a vibrant private insurance industry alongside their public system, whereas Canada forbids it.
It's quite clear that the US healthcare variant simply isn't working and isn't sustainable. I pay more for my family's health insurance ($2,000/month) than I pay for my mortgage, and it goes up 10-20% every year (both pre-ACA and post-ACA).
We're well past the point of saying "well, that experiment didn't work, what's everyone else doing that works?"
Our current path is demonstrably not prudent, with a good dozen or more examples of what appear to be prudent approaches to draw from.
Free, no, but the rest of the developed world has universal coverage and healthcare that costs half what it does in the US per capita, with similar outcomes.
Someone has to pay, yes. The US's way of paying is just horrendously complex, expensive, and inefficient.