[alistairSH]

That gating on medical training has always been there (at least for 40 years, if not more). But the number of doctors from doctor families has increased.

And just generally, socioeconomic mobility has decreased in the US across the population.

[mothballed]

Always been gated. But the slider has been dragged even further in the purity test direction. The intelligent un-pure now tend to become NP or PA, those programs still let you practice independently and slide more towards academics and less at whether a rich person set you up to be taken care of while you play mother Teresa until the switch flips the day you are accepted.