Often because someone is good at something, the first inclination is to promote them and put them in charge of more people.
This can be a big mistake if the person is not an inclined leader as it sets them up for failure and in front of a larger audience than when they were an individual contributor.
What makes a great leader?
Someone who is willing to put a group's development first and find each person's motivation and weaknesses and work on plans for both at the same time in my experience. What are your thoughts on leadership?