but the printing press wouldn't have made many changes, at all, if it hadn't met a literate population. Yes, most people could read at least a little when Gutenberg developed his press and everything from Jokes for the John to the bible could be mass produced there was a ready audience for all of it. It was considered to be a good thing for people to read proclamations from the King. What they weren't taught how to do was write, a skill kept separate from reading for some time to come.
I don't know if it was the arrogance and conceit of the ruling class that thought the common man had nothing to say and therefore nothing to write except his name, if that, or if they were afraid another Peasant Revolt like the one in England would arise and have bigger chance of success when more people could read their manifesto and add to it.
In any case, literacy rates shot up from a bare majority to a very high number with the appearance of cheap printed material anyone could buy, even though churchmen grumbled that most of it was "bum fodder" for the masses.
(Capitalism had existed before the printing press but it was land based, not based on an abstract like money, wealth being based on the amount of land one controlled)