Specific example: most people expect a basic haircut for a man to trim around the ears. If I never trim around the ears then maybe I'm being safe, but you can't say I give a safe haircut because I'm not even giving a haircut as most people expect it. In particular I'm avoiding one of the most dangerous parts. You need to watch me trim around the ears in a minimally correct way to make sure I know how to do it safely.
You can give an absolutely crappy haircut in a perfectly Safe Way.
I don't think you'll be able to convince me that someone needs 1500 hours of training to give a buzz cut.
I also don't think you can convince me my barber needs to be able to do every possible hair procedure in order to give me a buzz cut
I'm not trying to convince you that a hairdresser needs 1500 hours of training to give a buzz cut.
I'm not trying to convince you that your barber needs to be able to do every possible hair procedure to give you a buzz cut. We could have barbers who are only licensed to do buzz cuts. We don't have them though because no one wants them to exist, not the barbers, schools, salons, public or government. Consider that being a barber who only gives buzz cuts is like being a programmer who only writes web-scraping scripts on freelance sites. They could exist though, theoretically.
We don't know that because it is illegal. Most men cut use Clippers and scissors. There are businesses that operate all day doing these haircuts. You can teach someone how not to cut an ear off, poke an eye out with scissors and clippers very quickly. There is no regulatory middle option. Even if there is no demand, there could still be a regulatory middle option.
* Idaho has "Barber – Barber-stylist 1800 hours; Barber (no chemicals) 900 hours"
* Wyoming has "Barber – 1250 hours with chemical services, 1000 without chemical services"
Maybe 900 or 1000 hours still seems like a lot to you, I don't know. Given the politics of these states it's unlikely their governments are being strong-armed by labor cartels or over-regulating on general principle.