I see a lot of reference to Europe-based medical practices being thrown around with no context other than, "This number bigger," so I'm hoping to clarify a few points from my own experience:

For one, the M.D. path for an American student is longer than the bulk majority of European countries you're referencing. European medical training begins after high school graduation, while American students have to complete 4 years of undergrad first. Only then do they complete 4 years of medical school, followed by 3+ (in my case, 5) years of residency. Depending on specialty of practice, a fellowship of 1-3 years after residency might also be required.

That extra four years of undergrad had me starting med school with a baseline of $100k in student loan debt (public, in-state university) that continued to accrue interest while I trained.

Then there's the matter of medical school cost in the US. I went ahead and checked my loan account for you, even though it gives me an ulcer to look at. Just shy of $400k is how much I'll have to pay back for those four years of training. When added to my monthly payment for undergrad loans I anticipate paying about $5k per month in loan bills alone. Medical training in other countries is subsidized to the point of being free for those accepted into an M.D. program. The UK is a bit of an exception, but their average annual tuition is the equivalent of $13k per year and still way, way less than the requirement here. I'd happily take a lower salary if I could know there wasn't going to be a giant debt hanging over my head until I'm at retirement age.

There's also a big discussion to be had about not starting to save for retirement until you're in your early 30s, but I've already gotten a bit long-winded here. The point is this: The salaries are higher because we fully bear the cost of our own training up front--for longer--and are expected to pay it back ourselves.

Others have already made the point for me, but we're a small drop in the bucket if what you're truly worried about is the cost of healthcare in the country overall. For that, you need look no further than hospital CEO salaries, nightmarish insurance companies, and the ludicrous cost of medicines courtesy of pharma.