My daughter’s HS physics teacher had a PhD. When my daughter was considering it and we all learned how hard it was to get a job on a college campus, I started looking at specialized math and science HS’s in the area and saw that many had PhDs.
Salaries are much higher at the HS level (at least by us). My daughter spoke with one of her professors in college and they started to discuss the salaries of tenured professors…they were surprisingly low…not to mention how hard those jobs are to come by.