One challenge of RPGs producing 'high' art, similar to literature, is that you need a talented, skilled artist. The art of literature can be reproduced and consumed on a large scale: James Joyce writes a book and everyone reads it. Most art that we experience is produced by people with 1-in-10,000 ability (as a guess; that would be 32,000 Americans) that have honed their ability throughout their lives.
In RPGs, the artists are some people you know who play occasionally. They aren't 1-in-10,000 (unless you are very lucky, and then the rest of the group is not), and they don't hone their skills as if it is a profession.
Perhaps RPGs are more like folk art, which is not an insult; folk art produces some wonderful works.
It's hard to imagine RPGs rising higher: Given the structure of them - they require personal interaction and there's way to provide no mass reproduction and consumption of the great artists - it would be hard to make a living doing them or to have your work seen, which means nobody will spend their lives honing the skills (and you need not just one person, but a group of DMs and players to create the art). People work all their lives to be great painters, great guitar players, etc.; will anyone work that hard to be a DM? Will they meet a group of similarly committed players and form a 'band'? Who will pay them? Who will ever see them? Perhaps people will watch a highly skilled group play, but for the viewers that's passive consumption - the opposite of what makes RPGs creative and artistic.
OTOH, I'd certainly pay to play with a a brilliant artist (who can master DM'ing). What an experience!