AbdulAlhazred
Legend
Obviously the mechanisms and, to a large degree, the goals of the game are different. I just reject the idea that in D&D players are helpless before the all-powerful DM and cannot alter the fiction through the acts of their characters. For that matter, I discuss generalities of tone and direction with my players I assume most good DMs do as well.
Despite technical definitions I think there's a lot of gray areas when it comes to all of this.
I agree with you that players in actual RPG play that is not borked do have a good bit of sway. However there's also a lot of disincentives to using it. You need to play table politics to figure out what approach will work with a given GM to get them to hand over some real narrative agency, and it's not guaranteed to work. IME it's all too easy for whatever you got to be completely obviated later on, and not due to any bad intentions, just that the way D&D works tends to do that.
But, BEYOND all that, the primary focus in D&D is on situations that are constructed by the GM. I have not played in your game, so I cannot evaluate how you build those situations and with respect to what, but you do emphasize your priority of running a setting that doesn't center on the PCs, which seems at odds with the Narrativist locus of play/driving impulse.