They make a lot more because it costs a lot more to pay for med school here. I've priced it out as I was considering it...out of state tuition could run me over $300k depending on where I hypothetically went...that's only 4 years of med school, only tuition. Not undergrad, not living expenses...just tuition.
Given the number of physicians who kill themselves each year (higher than national average), taking away compensation/future compensation isn't going to help them.
Medical organizations limit the # of residencies which in turn limits the # of practicing doctors which then creates a supply demand issue allowing the salaries to be inflated; and inflated significantly more than non-US doctor salaries. It seems that they make a lot more due to this as a factor more than the price of education (which I do agree is absurdly high across the board). Im not sure I buy the argument "they make more because the schooling costs more". This article even points out that specifically as a non factor.
https://www.wbur.org/commonhealth/2018/03/13/us-health-costs-high-jha
Not sure where you are going with the physician suicide rate and salary. Physicians don't seem to rank in 10 top for high stress jobs. Most of the jobs that do are pretty low paid positions (and access to health care seems to be pretty high as far as reasons to commit suicide go). And if they already make a lot and still have high suicide, paying more doesn't necessarily fix the issue and you don't know paying less would hurt. Money doesn't buy happiness, maybe the issue is not fiscal at all.
Back to the original overall costs discussion, it seems pretty clear that it is prices. Everyone seems to be getting their little extra taste along the food chain which drives the overall price significantly for a final product that isn't any better (and in many instances worse) that the rest of the developed world.