Nope. There is effectively infinite demand for physician services. If we had more doctors that wouldn't reduce the workload on individual doctors. The actual solution to reducing demands on their time would be through reducing the administrative workload which contributes nothing to patient care. Much of that could be automated or delegated or not done at all.

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.

Yes it would, but the sacrifices start at the university already, that part is incompressible I'm afraid