Abraham Lincoln spent less than 12 months in formal schooling his entire life.
He became an attorney the old-fashioned way -- he started as an entry-level clerk in a law office, learned on the job, and eventually passed the bar exam. He never had anything resembling an undergraduate education, much less three years in law school.
He did alright for himself.
My wife is a doctor. She told me that maybe 1% of her undergraduate training and maybe 10% of her training form medical school is relevant to what she does on a daily basis. She actually learned how to be a doctor on the job during her residency, and she has long maintained her hospital rotations her third and fourth year of medical school did a lot more to prepare her for the real world of it than anything in the classroom in first and second years.
So what must be the point of all these hoops you have to jump through?
Nailed in. So many of these are just a modern form of a medieval guild.
Guilds of merchants and craft workers were formed in medieval Europe so that their members could benefit from mutual aid, production standards could be maintained, competition was reduced and, by acting collectively, a certain political influence could be achieved.
https://www.ancient.eu/Medieval_Guilds/
Do I think that doctors, nurses, teachers, and engineers should learn the rudiments of their profession before being unleashed on an unsuspecting public? Sure do.
I am just not sure they really learn those in classrooms or during the licensing process. They probably learn it, like the most of us actually do, while doing it.