In Canada, 15.4% of public healthcare costs go to physician salaries. Salaries of other healthcare professionals are included in “hospitals” and tend to run about 70% of that category, so perhaps 20%.
https://www.cihi.ca/en/where-is-most-of-the-money-being-spent-in-health-care-in-2017
In the US, physician salaries accounted for 8% of total healthcare spending in a 2012 report.
https://www.jacksonhealthcare.com/media-room/news/md-salaries-as-percent-of-costs/
Here is another perspective.
https://economix.blogs.nytimes.com/2008/11/14/do-doctors-salaries-drive-up-health-care-costs/
All this information can be Googled very easily.
The bottom line is that, while US physicians earn more than Canadian physicians, their earnings account for only a small proportion of the costs of healthcare. Cutting physician earnings would not, in itself, solve the cost issue in the US. I have worked as a physician in both countries, and I believe that other contributory factors include
1. A litigious culture that encourages excessive testing, i.e. waste
2. Patient expectations that every deviation from normal will be treated, and ASAP
3. Private healthcare organizations whose goal is to make as much profit for shareholders as possible, using #1 and 2
4. A free market in healthcare that is based on charging whatever the market will bear
5. A huge administrative burden of insurers, assessors and managers. Example: in the 1980s when I trained in the US, in my division, there were 10 specialist physicians and 12 billing clerks. The division made over $1 million profit in 1986. I received a bonus and didn’t know what to do with it because I had never received a bonus before (or since). Later, I worked in a large department in Canada with over 100 specialist physicians and four billing clerks. No profit, no bonuses.
6. Patients without healthcare insurance ration their own healthcare. They wait until they can afford it, or until their chronic conditions cause complications requiring emergency care. (Ask any rural family doctor in an under serviced area). Emergency care is much more expensive than preventive care.
Please note, I am not expressing any political opinions. These are just facts that I have learnt from many years in the medical profession.