I think this outlook might've led also to the later difference of the East still urging the translation of scriptures into vernacular (such as Sts. Cyril and Methodius). I can't find an era when it wasn't important.
And this idea that no one could read in the past is silly. I don't know where this meme comes from (Luther? Or was it the RCC? Maybe both?).
St. John Chrysostom circa 300s AD:
"Listen, I entreat you, all that are careful for this life, and procure books that will be medicines for the soul…get at least the New Testament, the Apostolic Epistles, the Acts, the Gospels, for your constant teachers. If grief befalls you, dive into them as into a chest of medicines; take from there comfort for your trouble, be it loss, or death, or bereavement of relations; or rather do not merely dive into them but take them wholly to yourself, keeping them in your mind."
“Let us not simply imprint this on our minds, but also discuss it constantly with one another in our get-togethers; let us constantly revive the memory of this story both with our wives and with the children. In fact, if you want to talk about a king, see, there is a king here; if about soldiers, about a household, about political affairs, you will find a great abundance of these things in the Scriptures. These narratives bring the greatest benefit: it is impossible – impossible, I say—for a soul nourished on these stories ever to manage to fall victim to passion.”