Why do women form "friendships"?

Isnt it really just a group of women having their own personal convention about how to be a better woman? In the bedroom, the kitchen, to their children, etc. Its really a convention about how to be a better mother/wife to your children/husband. Like can you imagine hanging out with the boys and discussing methods of being a better father/husband? No, we are busy talking about cars, politics and other nonsense.