Personally, I find a lot of the Moons really unsatisfying. In Mario 64, you took on each level in a mission, hunting down and finding one star, and then exiting to retry. It made each one feel really special and satisfying, even though some weren't hard to get.

In Odyssey, a lot of them are simply all over the place. You find them, and you move on and keep going. With neither a challenge, nor any sort of real punctuation to finding them, there is much less satisfaction to finding them.