Licensing has shown it achieves very little, look at the government instigated part P leglislation for electricians. Things still go wrong. Some of the best mechanics I have known had no formal training or qualification. I have met PhDs who don’t know the safe end of a screwdriver. Where does that leave you? For that matter I know of a main dealer whose service department told me they knew nothing about cars, I asked if they were doing a college course to learn more, Oh no, I was told I didn’t need to know anything. That sort of company would sail through qualifications!