In my experience, it's 70% programming, 20% office politics, and 10% project management. People who realize late they're no good at programming, or don't enjoy it, will pivot towards other kinds of work, like project management. But people who think they'll have luck managing people without having any grasp of the skill set of the people they manage, they either need really good people skills, or they're obnoxiously incompetent in both humans and computers.