To be fair, healthcare is very expensive even outside the US. It's highly specialised, requires complex machinery, you have multiple people per patient, 24 hours a day.
The US cost is usually double, but my understanding that is mostly to pay for Lawyers and Insurance companies. So money well spent I guess.
For things that are "not your own fault", it is entirely reasonable for the costs to be covered by society. I haven't been ill for years, but a friend had months of treatment for a brain tumour in his 20s. That's just the reality.
We're talking about being expensive to the consumer though, so it definitely isn't expensive outside the US. Not to mention all of what you said there is often not the case. I'd argue that things that require specialised care, machinery or a lot of doctors/nurses are the minority of cases.
The US cost is also definitely not double. It's orders of magnitude higher than other countries where people pay for healthcare, and effectively infinitely higher than countries with free healthcare. As an Englishman living in Japan I'm shocked at how expensive healthcare is here, yet every American I've ever met here raves about how cheap it is.