If I were to have a surgical career, I would definitely have to undergo residency and that's full time work, no exceptions.
And that imparts enough knowledge for a doc to be seeing patients and treating them "on his own". Also, after residency, many docs choose to work less hours while many choose to work more hours, especially when they have a private practice.
Moreover , the study of medicine is not exclusive to one, it's a collective effort by a group of individuals while treating a patient, also because you can't do everything alone, even when it's your speciality, you gotta have shifts.
Moreover , another aspect of this kind of working as a hobby is that if I encounter a case where "treatment won't work" i would also be free enough to further pursue that case separately and devote even more time to that special scenario since I don't have much responsibilities to attend to at home.
That too, even if there isnt a team of highly sub specialised docs already working on that case by then considering such cases might be fairly uncommon.
Having such a restrictive and elitist approach to medicine, like you condone, I beleive isnt great either and might be counterproductive as well as moving towards borderline toxic work culture (all of this somewhat present in medicine already) , that's my opinion here.
