Well, that's the point - if you get a computer science or physics or biology PhD, then it's likely to be useful also in a bunch of non-research industry jobs.
If you get a literature or anthropology PhD - then outside of teaching it's useful mainly as a hobby.
There is still field work to be done in anthropology, but I have it on pretty good authority that grants are very thin unless you have a last name like Leakey. My friend was on the faculty at Harvard; now she's a lawyer because she doesn't want to retire in poverty.
If you get a literature or anthropology PhD - then outside of teaching it's useful mainly as a hobby.