The current college model was developed for a world which changed slowly. Young men were sent away to not only learn the principles of great thinkers and absorb a shared culture of events and symbols, but to meet each other and learn how to interact with the other future rulers. The age for this became ages 18-22 for rather accidental reasons - it used to be much younger.
In this system, one might not have wisdom upon moving into the world of banks, regiments, clergy, government, and managing local agriculture, but one was theoretically equipped to get started. The foundation of learning to read Marcus Aurelius and Homer in Latin and Greek, plus Shakespeare, the Bible, and a theologian or two were thought to equip a man to make the great decisions of life forever after.
Please note that making application of these thinkers to everyday events was not much taught. The mere exposure was supposed to build a man up so that he would naturally assume his place among his fellows and make sound decisions by a sort of osmosis. It's a ridiculous system that sort of worked.
No, that is concluding too much. The educational system of monarchial Europe, developing into parliamentary Europe and its colonies, may have had good features that outweighed any ridiculousness I note here. Unifying the elites into work-together packages, perhaps. The playing fields of Eton and all that. Or, the educational system may have had little or nothing to do with the development of governance and leadership skills in those places. The most we should say is that this college model did not break the leadership system. That's something in itself, I suppose.
We think that extending this system to some of the middle class via the post-WWII GI bill and subsequent expectations of college-for-the-many in the 60's and beyond worked very well. That it provided many benefits is rather undeniable. But 60 years out, some of the negatives of this idea are starting to emerge. Was this all a net gain?
I wonder what we would design for post-HS education these days if we were starting from scratch? I am thinking that 4 years starting at age 18 should be one of the first things to go. That model applies well to the especially academic 5%, a number that includes...what, about half?... of the intelligent folk.