There will always be a perceived underinvestment in academic research. That's because "reproduction" of PhDs is so rapid that their number will expand to fill any funding available and then some. Aside from short lived transients, fields will exist in a state of Malthusian equilibrium, with most PhDs failing to stay in academic research. And this overabundance explains the relatively low salaries.

I worked in biotech / pharma for a little over a decade, a big chunk of PhD’s are doing work that doesn’t require a PhD…as in open to someone with a MS or PhD.

And then mamy jobs “require” a PhD, but I’ve seen what they do and it’s semi-mindless and very repetitive.

Every tenured professor is expected to have at very least one PhD student. A PhD takes on average less than 8 years and a tenure more than 20.

Though I think a more reasonable replacement rate is 10+ PhD graduates per professor. I do not think this problematic somehow, unlike what overproduction implies.