https://www.bls.gov/ooh/personal-care-and-service/mobile/bar...
FWIW all my peers that I went to high school with who got their cosmetology license 1) did so for free as our public education system offers cosmetology school for free and 2) no longer are practicing 20 years later
Also not all stylists work full time because it's a relatively well-paid job. One of the colleagues at the salon I was talking about has worked a 3 day week for years, and another works 2 days a week (but she does have another job).
On your other point about older hairstylists, it's a very physical job where you stand in an awkward pose for long hours. Many retire (or semi-retire into salon ownership and doing occasional special customers) by their 50s.
While the basis for regulation makes sense on paper anyone who's done anything with a low margin service industry knows that whether good practices are followed in a particular workplace has almost nothing to do with education (everyone knows how to keep things clean) and everything to do with management (does management actually want these things done or does it consider them a waste of time).