I definitely reread my favorite series. The thing about re-reading a book is that you don't actually ever get the full experience the first time around. Well-written books are full of foreshadowing, not just of plot points, but themes. The first time you read a book, you don't really know what it's about yet, what the book will eventually decide is it's overall thesis, and where the characters' journeys will take them. Critical moments that shift the trajectory of a story may happen quietly, only important in retrospect.

When you read a book a second or a third time you get to do so with all of the context of where the story is going, and it lets you catch so much more.

This example is from television, but The Good Place is my favorite show, and (spoilers) one of its central theses ends up being the modern world makes unethical choices unavoidable.

Very early on in the show we get a scene of Eleanor making fun of her boyfriend when he says they should find a new coffee shop, after the owner of their current one is outed as a sexist pig. She lists a bunch of other products they buy like smartphones and sports games and says that bad stuff is unavoidable so why bother?

At that point in the show, the scene is just a way to show you what a dirt bag Eleanor was on earth. But on a seconds viewing, with foresight, you can clock it laying early groundwork for one of the main arguments that the show wants to make.

This is one of the reasons I don't mind getting spoiled on stuff, and in some cases will spoil myself on purpose. When you know how the story ends, you get to pick up all the little things it does to get there, without reading or watching it twice. I went to film school and am a bit of a story nerd so for me that's the most enjoyable part of watching someone else tell their story.