Also, often times the only way to get that experience in the first place is to be put into the positions of leadership to develop your skills.
We're finally getting to the point where there's not much "new" each year or decade, so it's starting to slow down again.
I used to work with this person in his early 30ies and they were in charge of the infrastructure. This person started as a developer and then was tasked with managing infrastructure, while not having never actually worked as a sysadmin and/or having done operations work.
Well… after a while it became clear that the limitations of the infrastructure were a reflection of the limitations of this person’s knowledge and understanding of infrastructure.
Experience does matter.
Appeal to age runs deep in our species.
You can run a fraternity, a marching band, a 800+ member charitable organization project before 20.
Often at companies (And I presume in other situations as well), people are thrust into higher level positions purely because they happened to be in the right place at the right time and someone above them left.
Too many people/companies claiming to be "world class" or whatever when they are above average at best.
I have no knowledge of Lafayette (Not American) and no context or understanding what he did, so my default judgement is that his skill is exaggerated.
It's worth noting he had been trained in a French military academy for officers since 11, and was commissioned as an officer in the French Musketeers at 14.
Additionally he was extremely well connected in the French nobility and clearly had the expectation that men would follow him.
As for his leadership capabilities, Washington cited him in a letter to congress when he was still officially an adviser for rallying US troops during a retreat after being shot in the leg. His record is pretty good: https://en.wikipedia.org/wiki/Gilbert_du_Motier,_Marquis_de_...
Maybe this is true on a relative scale (E.g. good leadership skills for their age), but I don't believe it's true on an absolute scale and an absolute scale is the only useful scale in a professional environment.
I also believe that leadership skill is domain-specific, so having significant experience in your domain along with good leadership skills (Real skills, not from courses or workshops or whatever) does not at all seem feasible by the age of 20.
My current company is lead by someone with good leadership skills, and successfully managed a commercial team. Now he's trying to lead a company, and it is clear that he does not have the necessary experience to make the correct decisions.