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.

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.