I’m told that for a large company to develop a successful child’s film, initially, much market research is done. Groups of the general public comment on a succession of story lines and make suggestions until the plot is honed. It works.
Merchandise linked to the story is abundant. With the child, you can read the accompanying books at home. Inside these colour coordinated books, perhaps there are flaps to lift or a magic wand which whooshes. In another book a button is pressed to summon the familiar music from the film. You might clap, sing or listen with the child. Plays and parties with the story theme are fun. Children can wear variations of the clothes worn by the characters of the film. Those children are happy and feel secure.