The perspective from which it is easiest to explain gender inequalities is the conflict perspective. From this perspective, gender inequalities persist because men have the power in our society and they want to do everything they can to keep it. They are constantly in conflict with women and are winning. This allows inequalities to endure.
From this perspective, men are able to do many things to keep women down. Perhaps the most important of these is socialization. Men have come to dominate society so much that they are able to pass down pro-male ideas through socialization. They are able to get our society to teach girls to be less assertive than boys are. They are able to get our society to push girls towards lower paying jobs like teaching elementary school and away from more lucrative jobs like engineering.
From the conflict perspective, everything about our society is the result of conflict between groups. The gender inequalities that we see are caused by the fact that men have tended to win in the conflict between them and women.