IDK y'all I just think Okami portrays a very interesting mutual relationship between the gods of its world and the people who believe in them. It's all but outright said that a god is only as strong as the worship it receives, and when the people's belief in the gods starts to wane, they start growing weaker. It's even reflected in the mechanics: the resource you use to make your health/ink/etc stronger is praise. When you arrive in mortal Nippon, worship is at a low, and you are nowhere near the glory you used to be, and only through spending the Praise you get along the way do you start to actually level up and feel like the god you're meant to be.
But it's not all on the people to be worshipping the gods. The relationship is mutual: when people feel the gods don't show themselves in things not 'big enough' to warrant their presence, they start regulating them to things of fairy tale and legend, only praying to them in times of strife and when they're 'needed', and not often in between. And sure, the main quests give you enough praise to get you up from ground zero and get you over the proverbial finish line. But the only way you can max out your stats--reach that level of godhood you know you can be-- is to put in the effort to do some of the sidequests too.
Errands as nothing more than that Weird Dog running around town. Blooming trees and plants with no one around to watch you. Hell, even feeding animals that don't once speak back in your tongue. Praise no one is giving you because a favor was asked first. Praise out of gratitude for making the world just a little bit better, even when it's outside of what's expected from a god of your station.
If you find ways to show that you love the world you look after, the world will show that it loves you back.
And that is what makes you truly powerful.
