Obviously they exchange labour for capital and are rewarded commensurately by the free market.

Not the person who posted this, but there is a very, very clear line that can be drawn between school and industrialization, both essentially came into live during the same time. Sometimes the same people who owned the factories where the parents worked advocated for schools to which their kids could go (totally out of the kindness of their hearts ofc). The way school has been structured historically was (and in many parts of the world: is) still stemming from that time.

And this was a society that didn't need free thinkers, but people who did as they were told.