I Want to Play Too: A GM's Workload

[Cluedrew]

You can't run a vibrant, living world without doing prep.

Sounds like a challenge.

I suppose if you had sufficient skill at world-building and character creation (in the narrative sense) then you could take care of that. In fact there is nothing innate about the problem that would change it from any other type of preparation so of course it is possible even if fewer people have, though some combination of talent and training, have reached that point.

The world building would also be easy to... turn into a system matter. Mostly I am thinking of Blades in the Dark where the city of Duskwall is the setting for the campaign and you could do something similar as long as moving from place to place isn't a part of the campaign. Or you could do something in the rule book to help generate new locations.

Character creation is a bit harder because it is easier to fix a map than to fix all the people in it but with the right tables of prompts and names that were built for different groups in the setting it could be done as well.