I've brought this up before, and think it worth
talking about again: what is a payoff for you, especially after a long series?
First of all, I'm unsophisticated enough that I do want a dramatic payoff for my troubles. It may be very literary and smart to have an ending that just stops, with issues unresolved and no one going anywhere, or left worse off than they were, but I've seen it too many times, and it's never going to be anything but meh.
However when the protagonist is awarded the Crown of the Universe, I can feel equally meh, especially when I feel that what's going on is material gain, but no one has actually changed. I like earned endings, even if the surviving characters don't get what they want. They get what they need, or what they earned, or even just a purpose so I can watch them walk off into the sunset rubbing their hands.