I think the film presents an uncomfortable reality in an uncomfortable way that is difficult to understand.
Meanwhile the plot is about how nobody cares about Arthur and no one sees him as a person. No one cares what he wants because nobody gets it, they can’t look past the surface.
While it doesn’t present the message as well as it could, it leaves you with an empty feeling as you leave. Perhaps this is the message the movie wants you to feel.
An undoubtedly unique cinematic experience.