>> What's interesting is that long-form narratives seem to less popular in newer systems (and particularly outside the traditional D&D camp), which tend to aim instead for a reasonably short, self-contained arc in maybe half a dozen or so sessions. Particularly with the PbtA/FitD genre that's come out of Apocalypse World and its derivatives, there's a lot of emphasis on telling the one story that the system makes sense for, and then moving on to another story.

That's right, but I wonder whether this is more of an effort to find and occupy a niche in a market where D&D still sucks all the air out of the room. D&D and some other big-name games like Pathfinder, or Vampire I think. I'm not even sure anymore.