Medieval writing had diphthongs, strange, often regional abbreviations, and, based on what I remember from college, were difficult for someone used to reading L

Medieval writing had diphthongs, strange, often regional abbreviations, and, based on what I remember from college, were difficult for someone used to reading Latin in current print form. There was still need in Europe to standardize and simplify those things. That process was still underway well into the 18th century. There was also the problem of spelling. Early Latin print in Europe is similar to Chinese also in that it's written form was more or less understood by educated Europeans, but their spoken langues had splintered away and we're often not mutually intelligible.