Why make my bed?
It is not so much the made bed itself that is the goal, but the “easy win” factor. By making my bed in the morning I set the tone for the day. It is a victory of willpower (because I’m pathetic and require willpower to make my bed) that doesn’t tax my willpower much (not, like, breaking a habit of eating chocolate in the evening – for a purely theoretical example).
Walking in upon a room with a made bed is a reminder throughout the day that I am in charge, I am making progress, I am becoming a more orderly person.