https://en.wikipedia.org/wiki/Dreams_(1990_film) and
https://en.wikipedia.org/wiki/Waking_Life are two of my favorite films.
Dreams can be wild, but the writer manufactures their characters from their mind while conscious. The intention and the agency over the creation sets them apart.
I have had only a 1 or 2 lucid dreams, but I couldn't hold the dream state for any appreciable amount of time that I achieved consciousness in the dream world.
I wonder how many writers employ dreams in the creation of characters, if they dream about the stories they write?