Have you noticed that there's never an increase in NPCs in cities that are developed over time? And that the story barely increases the count to offer more in the immersion?
Few examples:
Mor Dhona. If you were here in ARR, it was built from a single shack. Despite its massive build, it's still pretty empty.
Idyllshire. The city didn't increase its numbers, and there was never any NPCs that celebrated your victories.
Doman Enclave. The city isn't anywhere near as bustling as Kugane, it has maybe 10-15 NPCs total. There's really no indicator of success. You literally paid for the entire city and not a single person recognizes you or says anything after donating millions.
Return to Ivalice in Kugane. There's only one pair from the ship that are in Kugane but no one else interacts.
I don't know if it's because there's generally not enough people, but Kugane really showed me that there's NPCs walking around, interacting with each other, having conversations, and it's kind of strange that we don't see that more often.
I wonder if that's a lore reason or a system limitation.