Why doesn't the story end with Gollum repenting and placing his faith in Eru Ilúvatar while the Newsboys fly in on the eagles? Why is...

Wisdom is drawn from Doctor Strange, Faust, and Kierkegaard regarding the nature of despair and embracing the enduring life of meaning.

The human story is true and will ever reassert itself, even as despairing Shadow, in order to remind us of our need for the Light.