I both admire and am bewildered by the authors who can spend the majority of their careers writing stories in the same world. They may span continents and periods of history, or they may concentrate on one extended family, but the underlying laws of nature and magic are the same. This creates a great deal of depth and the ability to explore the same world through the eyes of different cultures or time periods - and the latter isn't done nearly often enough.
I just can't hold myself to writing in a single setting. I'm too often thinking of ideas and story-sparkers that need an alteration to the underlying assumptions of the world to work. If I tried to impose this on the same setting, well ... I'd have a cast of very cross and confused characters.
This is part of the reason why I want to get back to my Ishene and Kemel stories at some point, though they definitely lend themselves more to the episodic than to the concentrated arc of a novel. Ishene is a time mage, allowing her to travel to different historical periods and places within her own world. Her magic also slows down her aging drastically, so there's the potential for there to be cultural / technological shift during her lifetime. One of the free-writes I have yet to finish is written from the POV of her apprentice, when Ishene herself is quite old, and it mentions factories and industrial technology.
Of course, another possibility would be to develop this setting from the impromptu scraps I've created in the four or five short stories I've written thus far, but I'll be honest: I'm not sure there's enough meat in their setting to hold my attention for long enough to do that much detailed groundwork and development. Still, fantasy time travel is a fun conceit that allows me to dip into the ebbs and flows of imaginary history.