Why People Treat Men Differently Than Women

There is only one reason why many people (both men and women) will listen to men more than women, and show respect to men more than women, and give more resources to boys than girls, and expect girls to do what they think girls "should do" and expect boys to do what they think boys "should do", and expect girls to be cheerleaders for boys instead of doing whatever it is the boys are doing, and expect girls to let boys lead them, and expect women to be more respectful to men than they expect men to be toward women,
~and why they do all of this every day while denying it through their teeth.
It's not a whole bunch of various reasons, not really.
It's just one underneath it all.

It has nothing to do with actual reality, except for the reality that humans have compulsions.

Dig deep. Look at it objectively. Look down at the human species from a bird's-eye view, from God's point of view, from the universe's point of view (the universe has no gender or bias), from an alien's point of view.
Look at history. Look at Earth now. Look at Chimpanzees and Bonobos. Look at Dolphins.

There is only reason that humans ever treat one type of human differently than another,
or expect one type of human to live by different rules than another.

You're a human, you can figure it out.