It's like claiming that one needs to cram hours upon hours of leetcode practice to be a quality software developer. It might be necessary for some companies to hire you, but that's to meet a filter that is less and less predictive over time, not an actual performance requirement.
Back in the day religious books were copied by scribes educated in a monastic tradition. Now printers can print them in a completely godless manner but the result isn't any worse.
The time demands also differ widely between specialties. You can't really be a part-time neurosurgeon. But we see a lot of doctors in other specialties like pediatrics, internal medicine, radiology, and emergency care downshifting to part-time schedules after they have established careers.