The US spends less on academic research than the OECD average. See, for example, https://ncses.nsf.gov/pubs/nsb202326/academic-r-d-internatio...

From a European perspective, the most noticeable sign of this is the scarcity of postdocs at American universities. Some fields and individual labs are better funded, but on the average, the universities lean heavily on students doing the actual research.

Because postdocs are basically slavery. The expectation here is that after a top Ph.D. (which tend to be longer than in Europe), you get a real academic job (assistant professor).