Children's literature is considerably more functional than a good portion of adult literature. If I were cynical, I might say: Children's books are written to be read; adult books are written to be talked about at cocktail parties.
There may be more truth that cynicism in that statement. My impression is that many adult books are written only to shock the reader (a short term goal, since shock quickly turns into boredom) or as calisthenics for the author's ego.
On the other hand, children's literature seems an area where books function as they were meant to; where they amaze, delight, and move our emotions. We can respect and admire any number of current adult books, but I find it hard to love them.

Like his fellow genius, Tolkien, C.S. Lewis has redefined the nature of fantasy, adding richness beauty, and dimension... In our times, every fantasy realm must be measured in comparison with Narnia.

Thus, death begets death; evil begets evil.