I guess you mean the period in human civilization where there was widespread literacy but also a high cost of mass producing and distributing texts, assuming people with money to invest in reporters can't be stupid or misinformed.
https://ourworldindata.org/grapher/literate-and-illiterate-w... Depending on where you draw that line, that never really happened (I would call 'widespread' around 80%, which happened in 2000 but then there was already an internet, although it was a niche and playful version of what it is today).