You wrote:
“Not defending the actions of the Church, but through most of the Middle Ages there was little or no literature of any type in the vernacular languages.”
That’s what people said for decades - but it really doesn’t hold water. Anglo-Saxons and Norsemen had a written literature before Dante.
Not very much of it. Hardly anybody could read, in any language. About the only people who could were clerics.
In fact, for a very long time in English common law the ability to read was considered proof you were a member of the clergy and able to plead “benefit of clergy” and eligible to have one’s sentence significantly reduced for many crimes.