A funny thing happened in the nineties; after Jurassic Park and Toy Story and other computer-graphic films had me got thinking about composing paintings in three dimensions on a computer instead of in two dimensions on paper, my dreams changed. Normally I don't think super-clearly visually, and certainly not three-D-wise. But I started having some dreams which were very film-like and *very* three-dimensional. I remember one of them, flying up and down in the air with other creatures, one of them similar to Batman, only in a brown suit. This was also a dream where I knew I could never have imagined that being awake.
I think art has a purpose of coaxing us to create the dream (the World) intentionally, to help us realize it's all dreamed up. And I think 3D films do the same.
Similarly, take violent movies. I think they help us to face the group guilt by putting control and aesthetics and thought into imagery we would normally never look at if we could avoid it.