Next up someone is going to claim that the Narnia series isn't kids books.
Kids books is probably not the best way to word it, you can enjoy them at every age, including your childhood, as you get older you may find new truths in them, but they're still good for any age.
I mean, you can enjoy them at every age, but they're still children's books. They are made for children (The Hobbit was created as a bedtime story for Tolkien's children!!).
This idea that complex and well crafted media for children suddenly isn't for children is very harmful, in my opinion; its results is what we see in this discussion right now, people baffled that children can engage in books with 300+ pages.
And I believe part of the reason this happens so constantly is people feel embarassed for enjoying something for children. Yes, you like the Hobbit, which is complex, well crafted enough that it became a classic read by people for all ages, but it's a book for children; just the way it's written shows a conversation between author and the child engaging with the book, you notice really quickly once you read it.
