It was entertaining in the beginning (first 45 minutes) and there were some funny scenes, but by the end, I was bored and tired of the women-against-the-patriarchy monologues. It was about what you'd expect from Greta Gerwig -- funky and weird and fun sometimes, but too overt in its commentary on sexism. There was too much talking about sexism and not enough showing. Also, Barbie is expected to choose between doll-life and human-life, but there's no good reason why she'd choose human life. We're presented with nothing of value in the human world, except that she experiences crying while she's temporarily there.
The Mattel plot was boring and unnecessary, the monologues were tiring, and the ending was predictable. Watch this if you want to be "in the know," but if you're looking for an actual good movie worth your intellectual time, skip it.