Underperformance is often a reflection of leadership shortcomings. As a leader, your role is to identify performance issues and address them effectively.
As a new leader, you may find yourself in a situation where you must rely on a less effective leader. Perhaps they were once successful but have been promoted beyond their competence, or there seemed to be no better option at the time.
One way to become a leader is to work harder and more efficiently than others. This is often effective, but it can lead to burnout and dissatisfaction because in essence you are running on a hamster wheel.