Both Narnia and His Dark Materials have terrible endings. The Last Battle might be one of the most anticlimactic fantasy novels I've ever read, which is saying something. (Though couldn't even finish The Amber Spyglass, so Spyglass is probably worse.) The Last Battle had an interesting beginning, an interesting premise, but it went completely off the rails with Apocalypse metaphors. I wanted to read more about the evil Tash or the dopey

, those characters were fun. But no no, CS Lewis had something important to say about what happens on Judgement Day, so forget these plotlines he'd spent the first three quarters of the book setting up.
Of course, the book does what it sets out to do: Complete the Biblical metaphors and end Narnia. It is obviously defended by Lewis's fans, but I have yet to meet even one person who claims it as their favorite in the series. When the movies were being made, people on forums would excitedly talk about what they would like to see in The Silver Chair film or The Voyage of the Dawn Treader, or The Magicians Nephew, but no one ever talked about what they would like to see in a The Last Battle adaptation. I think deep down even the fans defend it not because they find it well written or fun or engaging, but as a medicine that must be taken with your peanut butter. That's always the vibe I get when people bring up The Last Battle. It's like Pilgrims Progress.
It's not like CS Lewis was incapable of making Biblical parables engaging. The Magicians Nephew is a parable of Genesis, and it's one of the best and most popular installments in the series. Shame that The Last Battle couldn't have been more like that.
I pity whoever Netflix contracts to adapt it into a film!