Because a private medical researcher has to actually be funded. In other words, the expected value of the researcher is in excess of the researcher’s cost.

Nobody pays medical researchers without expecting an ROI unless it’s for a charity (in which case it’s funded by other excess value in the economy).

There isn’t really a meaningful difference between the government spending $100 to get $2 of value and spending $100 to get $0 of value. If we’re going down the unsustainable jobs path, it would be much easier to just pay everyone $80k/year to do nothing.