Children’s books tend to feel freer to throw lots of stuff at the reader and expect them to deal with it than a pulp adult book which is aimed at being relaxing and not too much effort.
I dunno if you know the children’s writer Diana Wynne Jones? (She did Howl’s Moving Castle but also a lot of other books that aren’t as well known, but are well-loved by the people that have read them). I interviewed her a little while before she died, and she had a thing about comparing writing for adults and children, in that children expect everything to be new and difficult, and you can throw weird things or words they don’t know at them and they just take it in their stride because they expect reading to be a bit of a challenge, whereas a lot of adults will just turn off if you do that.