(edit: yeah, silently downvote people asking questions... people shouldn't ask things. Or is it some sore I stepped on unknowingly?)
So Ron Edwards, who came up with the GNS system, realized that the there were lots of games about winning, and lots of games about simulations, but very few games about drama/stories. He published his ideas wide and far on the internet, made some games, and ran a very influential forum, "the forge". Along with a later spin off forum, story-games.com, a new breed of game designers showed up that focused much more on narratives and the dramatic moment.
Some examples of these cult story games are The Burning Wheel, Dogs in the Vineyard, FIASCO, Apocalypse World, Mouse Guard, and Dungeon World. These started out fairly hardcore, with but had narrative elements built into the mechanics the game instead of an afterthought. As time went on, and with lots of experimentation, people found out just how the light you could go on the rules and keep the focus on the mechanics that drive the story.
The much praised D&D 5th edition, that renewed the hobby and got kids back into it, brings in many of the elements honed out in the cult fringe of story games.
So yeah, I think at least the GNS theory has had a major effect on the RPG gaming world.
If you want to get a taste of these games, take a look at the Apocalypse World.
Here's an example of a "move", that a player can do to bring the dice into a story:
"DO SOMETHING UNDER FIRE
When you do something under fire, or dig in to endure fire, roll+cool. On a 10+,
you do it. On a 7–9, you finch, hesitate, or stall: the MC can offer you a worse
outcome, a hard bargain, or an ugly choice. On a miss, be prepared for the worst."
Essentially the rules prioritize putting interesting people in bad situations and seeing them make hard choices. It's the distilled essence of drama.
The player rule book is here: http://apocalypse-world.com/ApocalypseWorldBasicRefbook2ndEd.... I'd recommend going about halfway in first and read the "basic moves", then scroll up to 1/3 of the way in, and read a character's sheet.
(But then Ron Edwards infamously said that traditional/D&D-style RPGs literally cause brain damage, so I suppose there's a lot of defensiveness to go around...)
In Burning Wheel for exemple, there is no game balance. The knight will absolutely destroy the village-grown militia man, even if they have the same amount of "xp". Also, the complete swordplay game system takes hours to learn just to emulate a few seconds of fencing. They chose realism over smooth gameplay.
More like throwing the baby, the role, out with the bathwater.
All because Ron got pissed because the marketing blurb on the back of a White Wolf game didn't quite deliver what he expected.
Would you please not break the site guidelines like this? Unfair downvotes suck, but for a comment like this it's almost always the case that users will give corrective upvotes, which leaves the complaint not only against the rules but factually wrong.
They are not scientific theories. They are akin to the schools of thought in literary theory, and film theory.
I can't prove with p<.05 that my review of _Schoolhouse Rock_ is 'correct', either.
It's true that there is no way to logically prove the value of a work of art (and who says art has or needs "value"?), but lack of proof doesn't mean something doesn't exit; it means it's harder to think about. There is no proof what will happen tomorrow, but we make judgments without it, as we do about most things: Should I take this job? Should I marry this person? Do they love me? Do I love them? Should I ask out the new neighbor? Ubuntu or Fedora?
There's no algorithm to understanding art; there are tools, but there is no certainty. Without a logic map, it can be very challenging - in the best way, IMHO, because it brings forth and develops my deepest thinking and compels me to challenge myself and my perspective. I can't prove a Miro is better than your neighbor's kid's drawing ... and I guess I don't really care to; I'm going to study the Miro.
By reading the definition of theory, this is a slightly inappropriate use as the goal is not so much to explain why people are having a blast as to make them having a blast.
Maybe we start speaking about game engineering instead?
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!
The two most promenant ones I’m aware of are The Adventure Zone and Critical Role. The first leans heavily on family, personality, and humor; the second leans heavily on structure, characterization, and voice acting (all the players are pro voice actors).
It definitely is a nascent art form, and the first 5-10 episodes of both are somewhat rough, but recent episodes have gotten quite professional.
Personally, my favorite is The Adventure Zone. The first arc, “Here There Be Gerblins,” is clearly pretty raw, but the series gets so much better by the end.
I'm not sure that is the reason for the difference. The Odyssey has plenty of gaping holes and shoddy worldbuilding, plus some inconsistencies. For example, the plot of the very end flops IMHO (and less humbly opinionated people agree); you have to strain to give it much credit.
What I think separates it from Star Wars and most other stories ever created is its reflection of humanity. The characters and social interactions are so true and so rich - not at the superficial layer, where there are gods and magic, but at the core of anger, pride, love, compromise, fear, uncertainty, joy, power, etc. - you can look at it and deep into it forever and will never run dry.
If I can run on a bit, Dante wrote, nature takes her course from the divine mind and its art ... your art, as far as it can, follows nature as the pupil the master, so that your art is to God, as it were, a grandchild. The Odyssey fulfills that, IMHO; a wonder of mortal creation.
Tangentially, Odysseus is one of the most unpleasant characters in all of literature, in deed and personality. Even on Game of Thrones he would be at the bottom of the barrel.
 About himself! It's in Inferno; Dante conveniently put those lines in the mouth of another character speaking to the author.
EDIT: Major edits
Star Wars is just a kids story, you really cannot compare the two.
RPG's are escapism, while real art is hard work. (Fun, but still hard work.)
There is art involved in making and playing RPG's, but the end result is not artistic.