A few comments:
Almost no dental hygienists work full time. And the attrition rate is high, because it is a difficult job. Even those who are good at it, only last 15 or so years because of the stress of repetitive precision cleaning on hands, wrists, shoulders and necks.
Computer Software Engineers also have a finite lifetime, no more than 15 years or so, because of a few combined factors: their skills are considered obsolete after a few years, the hiring industry favors the young, and competition with India.
CARPENTERS are said to be a job on the way out. That’ll never happen. People love wood and well-done carpentry.
I’d put auto mechanics on the list of relatively “safe” jobs.
Cars need to be maintained and in a recession, fewer people will buy new cars ( and even if they do,they still need to be maintained ).
And I don’t think you can easily hire an Indian worker on H1B to be a car mechanic. Neither can a car maintenance project be shipped to India.
I must be obsolete then with 26 years. We just hired a guy with 39 years experience in HW, microcode and SW (more or less in that order). My boss must be an idiot.