I always viewed FF XII with the lens that you (the player) are only looking at one piece of the world of Ivalice, and Vaan is the lens you look at it through. We do see small parts of other areas like the interactions between Drace and Gabranth, but aside from that there is a lot of things going on that you never encounter because the party never encounters them.

Similarly, the story is that of Dalmasca, and Ashe is the main character. But we experience that through Vaan's eyes.