Too many technical managers think that if they assign people to good work and leave them alone, people will be happy. It's true that people need challenging and interesting work. And it's true that micromanagement or other interference is not helpful. But people, even the most introverted people, need a relationship with their manager in order to stay at the company.
Here's why. An employee's relationship with his/her manager colors an employee's work experience. Great managers meet with their staff weekly or biweekly, and continue to build rapport, to learn about the people in their groups — their strengths,
weaknesses, desires, and pressures. The more knowledge a manager has, the more likely the manager can provide effective feedback and coaching, as well as help each person find work that fits for the person.
So, yes, management is at least partially about the work: about organizing the work, assigning people to the work (they may self-assign), and delivering results. But great managers know that they work with people. Great managers work on building a relationships, not just managing the work.