I don’t know if this applies in all states but in mine, kids under 18 must take driving classes and have 6 hours of driving with an instructor. In addition to the hours required. (And I don’t care about everyone else, we kept a log.) Those hours do make a big difference. Even though they started their instruction within the year of the state age minimum for licenses, no one had their hours in before.
Then, once they get their license, there are still ground rules, the state’s, and the home’s.