Friends is the key word in your argument. Selling your services to the general public, meaning complete strangers who don't know you but want some form of assurance in your skills, requires a license.
And it should. I assume that you want all illegal aliens to drive without licenses. What are you, a Mechista?
Actually, friends wasn't in my argument. My mother had a reputation as someone who could give decent haircuts to longhaired hippies who wanted to be more presentable when they went home to visit their parents. Maybe you should read my posts. I've been saying "mine the border". Licensing barbers and beauticians is stupid. You can walk into their establishment and look around. If they are using proper sterilization equipment, you can observe that. If not, you can walk out. Would you also like the government to license software writers? Bad software can kill people and waste $billions.