PhD types doesn't mean they make foundational research.
> They are numerous, smart, very cheap, and work very hard.
Yeah, this is a good reason to hire such people, but they generally don't do foundational research work at companies, and if they do it is extremely narrow.
Just like government work the problem is the environment, Governments hires management and planning types just like companies do, but that doesn't mean they can scale up like a company can. Same with foundational research, private companies aren't a good place to do that.
It's difficult to overstate just how menial, fiddly, difficult, risky, time consuming and unclearly profitable foundational biomedical research is. A research project could easily take 4-5 years, have a 5% likelihood of success, and have no clear monetizability, yet end up being a groundbreaking foundational result and necessary to investigate.
In other fields, either there's some tangible hope of profit down the road, or at least you can attract talent and prestige. Not so much here.
What companies don’t have is PhD students. They are numerous, smart, very cheap, and work very hard.