This was neither a fantasy nor a comedy. Barbie was not fun and full of life. She was miserable through 85% of the movie, which meant I felt miserable. I want a Barbie who is joyful. Isn't joy the point of fantasies?
Ken was not an accessory to Barbie, but a co-star. This made Barbie the character less important because Barbie is supposed to be the star, like Tinkerbell to Peter Pan. Ken was happy throughout the entire movie.
The lines about patriarchy were mostly exposition. This directly caused the run time to be too long.
There were too many subplots.
The movie ended with Barbie about to have an unpleasant experience.