Myabe it wouldn’t hurt if they are more clear if a book is YA, maybe in the cover or something?, I know I can google it but my kindle is not great for that and sometimes I don’t have my phone around. Although I have found some hidden gems this way, but to be honest, YA its not what I prefer usually.
I would argue that one grows to appreciate good prose the more you read and understand literature.
But to say the reading is itself a form of art, I don’t really agree. Art is about expression, in my opinion, and reading, just like watching a movie or visiting a museum, is more about appreciation and receiving input.