In the 1400s, sons of good families were sent to be taught Latin by the Church. The monks who taught them weren’t trained as educators, and they made heavy use of corporal punishment. So it wasn’t much fun to learn to read back then.
In this period, no one assumed that everyone needed to be able to read–quite the contrary. Reading was for religious purposes and learning to read English was seen as unnecessary at best, heretical at worst.
But people who knew how to read and write English were guaranteed a spot in the new middle class. Businesses, now springing up in the towns, needed literate people to work in offices, reading and writing contracts, invoices, rules, and regulations. The Church thought that learning to read English was a waste of time–Scripture was all that mattered. But they just didn’t see what was coming. English was the language of business, and capitalism would soon replace the feudal economic system.
By the mid-1700s, a majority of the English population could read, and literacy was increasing quickly. The Industrial Revolution followed soon after: Once people generally could read, the potential was there for a whole new type of workforce.
I think we’re now going through a phase a lot like the beginning of the Renaissance, which is why I think we need to teach all students to code.