Also, laypeople were not allowed to read it until about 500 years ago because the church was worried they would interpret it for themselves!
Not quite true. It's really the standard protestant line, in fact.
All Abrahamic religions except Christianity require a working knowledge of the language of their scriptures, and don't accept translation as valid.
In Christianity, the scriptures had three languages, which were very early condensed to one, and in making the translations, some of the most heinous things about Christianity developed.
Religious education in latin was available to the populace, for the most part, on demand. They just had neither the time nor the inclination, for the most part.
Do not do in public that which you do not which commented upon by the public.