I'm not educated in painting but will just assume it's similar to music and someone like Mozart. I genuinely believe you wouldn't get as many as you'd imagine. There were few people making music at that time and only a small portion of the population ever had the chance to listen to it (.5-1% around 1750, 5-10% around 1850). We didn't get 10x the number of Mozarts. We got some people who were as talented as him for sure and pushed boundaries and some got famous for it We also got many talented people who wrote very great music which doesn't get played at all anymore, many of those didn't push the boundaries.

Even with people like Beethoven who're seen as disruptors and wildly popular by general audiences there were talented disruptors at the time who actually did things he's 'known' for and they don't get played at all. Bach himself had largely fallen into obscurity for +-100 years. There's probably only so many Michelangelos or Mozarts people can be taught about in middle school, high school, university.... I believe it's more about the institutions that basically allowed someone like mozart or michelangelo some kinda 'patronage oligopoly', something which barely exists these days. Free market didn't really exist here well into the 1800s, even then you still had gatekeepers. In the end history picked a few winners very loosely related to their 'musical worth'.