i would question how much it has displaced books versus the general literacy rates among the populations, sure there were more books, but if only 10-20% could actually read, does that make difference? I grew up mostly on tv, and i learned a lot of from it, simpsons taught me a lot about world culture, norm macdonald taught me not to give a shit about the news narrative and say what is real, and thousands of other references that went over my head but still contributed to my understanding of the way fo things. its an interesting question presently becasue we literally have unfettered access to all knowledge in our pockets and dont even have to know how to read.