That might have been a part, but it's more that the idea of self-expression as the prime value in art is mostly a 20th century thing. The falling off of skill, realism, and other similar metrics is also a 20th century thing and largely came from photography and mass manufacturing. There's probably an essay or book out there covering the two intertwining topics, but I can't think of any offhand.
It's also worth noting that artists themselves were more directly competitive. Da Vinci and Michelangelo had a bit of a rivalry, for example:
You can't really imagine this happening between top contemporary artists today. "Gerhard Richter says he's a better painter than Takashi Murakami," is a headline that wouldn't make much sense.
It's also worth noting that artists themselves were more directly competitive. Da Vinci and Michelangelo had a bit of a rivalry, for example:
https://artrkl.com/blogs/news/art-history-feuds-michelangelo...
https://www.historyextra.com/period/renaissance/leonardo-mic...
You can't really imagine this happening between top contemporary artists today. "Gerhard Richter says he's a better painter than Takashi Murakami," is a headline that wouldn't make much sense.