Comment by circus1540

PhDs and postdocs aren’t fungible. The ones worth working with go to the same top 20-40 programs in their field. Even finding PhDs that have the bare minimum qualification of “caring about the field” can be tough as there are all sorts of weird incentives pushing people towards PhDs. Applies for most other things in science as well. Number of papers has greatly increased. Number of papers worth reading has not increased nearly as much.