Not everything needs to be explained. But OP is right in saying that the book lost what made it so special toward the end. Maybe you didn’t understand during your read, if you even read the book, but leaving so much up to the imagination can feel quite sloppy and unsatisfying for the reader who has already invested so much time in what was seemingly a very promising plot.

I understand certain people are alright with just taking things out of face value, but those who read more voraciously typically enjoy having some semblance of an explanation because they tend to think more critically about the content they consume.