I'm not sure what I was supposed to get out of this film

The cinematography and acting were great. Some on here have criticized Rinko Kikuchi's performance but I felt she did a great job of conveying the deep depression Kumiko was stuck in. I've experienced crippling depression before and I was able to relate to her character in a lot of ways. I especially loved the use of music and sound as a representation of her anxiety. The way the music would get louder and more chaotic the more people she was around, or the milk steamer when she was alone with her friend's child. All excellent.

The story was where I had the issue. When the film begins Kumiko is already wallowing in despair. We never see her gradually fall apart or even what led to her mental decline. Her character had no arc and none of the other characters are developed enough for the audience to feel any sort of attachment to them.

The tonal shift of the ending felt completely out of place and didn't work for me at all. I was expecting something that could have really resonated with the viewer in a haunting way. Instead we're given a dream sequence that was so obvious and on-the-nose it just fell flat. An ending that fit with the bleak tone of the film or was purposely left ambiguous would have been stronger and worked better.

So I'm left wondering what I was supposed to get out of this. There's almost no story, no character development, and an unsatisfying ending. Filmmakers David and Nathan Zellner clearly have a voice, but what were they trying to say?