I share your two hypotheses to the point I consider them ansatzes. Most of my peers have Ph.D.'s in hard sciences or engineering as I do. Most of them wasted their time on their thesis research; it's just a certificate meaning "certifiably smart, persistent, and able to do self guided study." I don't particularly regret getting my underwear drawer liner autograph from the governator. It was a poor financial decision, but I had fun playing with big toys, and it provided enough meaning to my life I avoided ending up a glue sniffer or drunkard.
Attempting to convince more people to do this is a fool's errand: we can't even employ the ones we have. I've been lucky in that I have mostly worked on interesting things and been reasonably well paid for it, but doubling or tripling the number of science people in the world is foolish unless you give them something useful to do. My last job hunt, I ended up talking to an awful lot of people who thought a good use of my time would be building data pipelines to some Hadoop atrocity. You don't need a Ph.D. in physics or machine learning to do that. Yet a lot of Ph.D. types are doing this sort of plumbing for a living, because there are not enough jobs doing actual science.