If we're talking about mass-producing medicine you need more physicians at some point. Your larger points may hold but I think you're underestimating the need

If we're talking about mass-producing medicine you need more physicians at some point. Your larger points may hold but I think you're underestimating the need for more physicians in the future. There's firstly the obvious aging-population demographic; the older people get the more health care they'll want and thus if you hold the population of physicians constant (as a % of the overall populace) the demands upon the for physicians' attention will become greater as time moves forward; you might say "so hire more nurse practitioners!" but I suspect that won't be the answer, and I think that'll be clear after the next point. The second point is that as medical knowledge has increased over the years medicine itself has gotten much more complicated. Problems that had no answer can now be examined and more-complicated disease mechanisms and cross-interactions (etc.) can be looked at. This is particularly true in gerontological settings -- old people have lots of problems mutually-compounding each other -- but it's complicated problems aren't the unique purview of the elderly. To practice future medicine well will require more time and attention on the physician's part; getting that time back in the face of increasing demand for physician's time probably requires more physicians, doing more-thorough work on fewer patients. And even in the present day most major teaching hospitals only really get by by slave-driving their residents; get rid of the residents and there's not enough doctors available at prices the institutions can afford to keep the hospitals working at full capacity.