One of the three primary Negative Change Arcs is the Disillusionment Arc, which is essentially the same as the Positive Change Arc, except that the Truth is… disillusioning. The difference depends entirely on how the protagonist reacts in the end.
In a rags-to-riches story, it is often the literal case of money flowing into hands that makes the story. Yet, many other variations exist. In love stories, the riches are love. Twilight is a rags-to-riches tale. Bella wins love. Edward too. And after a century of waiting, that feels especially satisfying.
The Voyage and Return is very common in children’s literature because it generally involves a journey to a magical land that pops up out of nowhere. The magic element is pretty sunny and light to start with, and then the darkness shows up for the hero to conquer.