I must stress that I have not watched the following video so I am merely commenting on what I have heard about the thesis Corbett is outlining here.
The dominance of the printed word led to different ways of thinking and being, and led us away from the day to day realities of life. Yes, some of us, some of the time.
The word ‘conspiracy’ suggests a They who forced books upon the world and corrupted our innocence.
So: the printed word enabled knowledge to be stored and shared and made it an advantage to send bright young people (males, predominantly) for lengthy apprenticeships to master that knowledge. As literacy spread and schooling expanded that lengthy period, let’s call it childhood, became longer and more commonplace. Drilling, grooming, propagandising…
The above is a crude summary of a very reputable analysis made by media ecologist Neil Postman. The invention Of Childhood might, he goes on to argue, be succeeded by its Disappearance in a postliterate world where hitting the right button on a cash register is enough to hold down a McJob. (Not his actual words, nothing like them.)
This line of reasoning has been developed further by popular writers like Nicholas Carr, in The Shallows, and more learned theorists like Shoshana Zuboff and Sherry Turkle.
A worrying endpoint that is being speculated upon, NOT by such writers, is the winding down of schooling past the age of 12 or so, for some young people. Elite knowledge workers, programmers of the robots for example, prescribers of vaccines, Reuters Fact Checkers. They will still need the lengthy apprenticeships to develop Right Think (advanced literacy/numeracy…not so much).
What will happen to everyone else?
My guess is that Corbett will have a theory about that too 