Read the OP title, it asks what job do people take too seriously. I answered. Anyone who ignores we did just fine without our current system of teachers for centuries is already doing exactly that, taking it too seriously. It has nothing to do with your strawman of me thinking a teacher was mean to me.
And you somehow genuinely feel that the average person's prosperity was, relatively, better in that period?
Working 7 days a week, morning to night, producing that prosperity and trade for the educated class in exchange for a pittance. Whilst eating your table scraps in the dark, you can hope you don't die of a disease you have no idea how to prevent contracting.
You can measure the prosperity of an era by contemporary descriptions of their health, including how tall people were. So we definitely have proof people fared better then.