I don't think age is as important as maturity and competency.Just one more thing we are completely screwed up on. You reach majority at the age of 18; you can vote and join the military. You can get married without parental consent.
But even in the age of Uber and Lyft, you can't have a beer.
We need to get straight on all of this. You're either an adult or you're not. Make one age for everything. I propose 19, so that most young adults are out of high school.