The Expanse's sixth book, Babylon's Ashes, features a large number of viewpoint characters. I think the storytelling loses something due to that. You get a holistic view of the story instead of following and cheering for few protagonists.
They could've ended it all here. The only possibly unresolved issue is Naomi's son but I don't see a good reason Babylon's Ashes couldn't have been the final novel. It wouldn't have been a very flashy ending though, I admit, but a good place to finish regardless.
I don't really have anything else to say about the book.
I hope the next one is more interesting.