https://pmc.ncbi.nlm.nih.gov/articles/PMC7916906/
To explain how science tries this retrofitting trick, see Daniel Wegner's The Illusion of Conscious Will. Science is beset by tricksters like Hoel who find their audiences in technologists.
See Allan Hobson's The Dream Drugstore for a non-psychological explanation (his is a neurobilogical one).
As a scientist, the very "function" you're describing could easily be perceived as non-survival, as keeping our attention on things we should be ignoring. Hoel's theory is par to idealized. He's not seeing the impairing role of what he is describing.
Hoel is fundamentally a technologist hiding behind the skirts of science, employing functionalism when it's been long discarded:
"Functionalism is fundamentally a theory of communication. The story of the mutation within functionalism from an organics to a technics of communication within the primate body is a story of semiotic theories and technologies" Haraway
To summarize, a functional description or analysis like Hoel's is an argument about the technology of dreaming, not its organic role in the brain. It's not science. His is an extractive theory, "how do we use dreams separate from their organic relationship to mental states"?
consumer451•2h ago
https://youtu.be/lXUZvyajciY?t=3025