Endings are terrific.
I'm just finishing up The Chained Adept now, having extricated myself from the swamp of my misconceived 3rd act. I love doing endings. I know exactly where I'm going, what's left to do, and what I need to wrap up.
Some genres, and some authors, too, like to end their books with a bang. Kill the villain, defeat the army, save the alien princess — done!
I find that I prefer a bit of a cool down at the end, a reflection on what's happened, perhaps the foundation of a new vector for the next book. My characters need it, a way to recover from peril and stress. (As one of my friends would say with a wink and a leer, “it's just not the same if you don't get to smoke a cigarette afterward.”)
It's the light my characters work toward, whatever form that takes, whatever the darkness that impedes them. They need some of that light at the end to sustain them.