The lack of ordinary life is the setting they choose. You can have streets filled with many many goons, if there is a riot for example.A couple of people have repeated this, but in every gif or video I've seen, it's Arkham Knight that looks comparatively lifeless. I mean, aside from the graphical aspects, are there actually even randomly roaming or living NPC's in the world, cars, traffic etc? All the streets look devoid of ordinary life? Besides the enemies that is.
Very comparable to the numbers of pedestrians in Infamous.
I would say NPC count is comparable and car count in Infamous is higher.