Inevitable?

My husband overheard someone talking yesterday about feminism and the fight against "patriarchy." It made me think: It's a truism in relationships that the person who cares less about the relationship has more power. And aren't men, for whatever reason, less committed on average to staying faithful to the women in their lives? The evidence seems to point that way. So doesn't that make it inevitable in the realm of western heterosexual relationships that men will tend to have a bit more power than women? Doesn't that cause a small degree of male dominance, i.e., patriarchy, to be inevitable? And are there other areas of life where the matriarchy, i.e., women, will inevitably end up more powerful on average? What would they be? My first thought is parenting, for biology makes it so that mothers are more likely to be physically proximate to their children than are fathers.