Nation-states are a fairly recent invention historically speaking, and their benefits are somewhat questionable - it's entirely possible that they simply don't

Nation-states are a fairly recent invention historically speaking, and their benefits are somewhat questionable - it's entirely possible that they simply don't provide more benefits than the price of administration. Humans lived in city-states for most of our history, I see no reason why we shouldn't expect the city-state to be resurgent in the current century.