Literature is an act of solitude and privacy. Never mind if it's about me; is it about you?That seems to me to be a false opposition. The best art, indeed arguable any good art of any kind, is both. That's an interesting thing about it, and it's the reason why dishonest art is rarely any good.
By being deeply, even impenetrably, personal for the artist it somehow becomes true enough to be deeply, even impenetrably, personal for the reader/viewer/listener.
To regress to an undergraduate argument, that's perhaps the only workable definition of Art, if a capitalised version really exists. Everything else is craft.