Ortega hypothesis
en.wikipedia.org
en.wikipedia.org
a) prior to 1900
b) 1900 to 1970
c) 1970 to the present
In particular, the academic enterprise was so much smaller in period (a) and it was dominated by people who were born of nobility.
In the period (b) it was rapidly expanding and it was possible for people (good or bad at science or politics) to get in relatively easily.
In period (c) it has been a game of musical chairs in which being good at politics trumps being good at science.
An example of science in period (c) is high-energy physics.
People talk about Edward Witten, for instance, as if we was comparable to Feynmann or Einstein, but Ed Witten has never predicted that something would be observed that later got observed. (Nobody has in period c!)
There is a huge amount of research in "anti-desitter spacetime" because string theory might work in ADS, but the part of the universe we can see seems to be a "desitter spacetime" where it doesn't seem string theory will work.
This doesn't seem to bother period (c) scientists for some strange reason.