Unfortunately the closest thing to a meritocracy that the United States provides. (meritocracy = success based on merit)
School was primarily set up to keep kids busy while parents
work. The fact that it goes for so long is probably the result of our
society going through industrialization. It also is used to teach children what is expected of them in this
society: a.k.a. glorifying the middle class (even though only 30% of
us are actually IN the middle class!)
It is the No. 1 thing correlated to a bigger paycheck - the higher you get in it, the bigger your earnings later in life.