The situation certainly sucks for the actual PhD holders. Go through 5-8 years of intense work and minimal pay, and the outcome is maybe a 10% chance of getting the job you want?
It's unsustainable. I got my PhD 20 years ago, but I would certainly advise my children to avoid it.
You're assuming all PhD's want to become a professor tho. Plenty of people go to graduate school as a mechanism to increase their prospects outside of academia. Or even if they do want to become a professor, they hedge with other roles that require/benefit from the degree.
It's unsustainable. I got my PhD 20 years ago, but I would certainly advise my children to avoid it.