The Star Wars universe is pretty limited, and I don’t think there’s really anywhere for the story to go.
Hypothetically, the universe has limitless potential for new stories to tell and settings to explore, but since the people in charge of this IP are unwilling to step outside of the franchise’s comfort zone and make anything too unfamiliar, it will continue to stagnate, and the universe will shrink. This isn’t just Disney’s fault or modern Lucasfilm’s fault, by the way. This was a problem under George, as well. The franchise is too fettered to its past.
So, if movies can’t actually have their quality measured, then what’s the point of lists like the AFI Top 100? Why create official rankings of movies that are generally considered great if there’s no way to actually quantify that?