I'm very much late to the party here, but RPGs being closer to art than science (a view that I'd subscribe to), doesn't preclude them from "moving on". Art has moved on. Art, graphic design, music, sculpture...these are all different now than from what they were like in the 70's, the 30's, the 19th century, 13th century or in ancient Rome.
Sure, some works of art are "timeless". Some games can be timeless, too. Some scientific discoveries are timeless as well.
The Illiad is timeless. Doesn't change the fact that literature has moved on and if you tried to (re)write the Illiad today, it wouldn't be a masterpiece. People wouldn't really care for it, not in the same sense. There's a very funny Borghes story about that.
The fact that Basic D&D is still good and popular and played today, doesn't mean that we don't need new games or that all games should try to ape it.
Otherwise games would have never moved on from chess. And while chess is pretty much timeless, wouldn't that also be super boring?