So your thought process is limited to this is bigger than that
It has no room for patient load, hours worked, characteristics of patient population, onerous governmental quality measures, medicolegal pressures, cost of living, educational debt, etc.
All these things are true but at the end of the day doctors want to make money. If they chose to do so they (correct me if I am wrong, which I could be) could work less hours and take on less patient load. Of course I dont know if doctors are actually forced to work these hours or if they choose to do so in response to american debt or otherwise.
Attending physicians from other countries would not have education debt. Cost of living may or may not be high based on what country the attending came from and what city he has located to, in the USA.
Patient population would be different, but one as to think that it doesnt take 4 years of residency just to understand the patient population. Like I said, we could fast-track people who have completed residency in select countries. One has to think it shouldnt take 4-5 years to learn all the parts of residency that dont have to do with surgery (for instance) and the direct care of a patient.