Managers must create and develop effective teams. Managers then coordinate these teams to achieve results. There are platitudes about people being our most valuable resources, the math checks out. As a manager, your mandate is to effectively manage your team, i.e. the human capital.
The most important management skills are1:
Auzenne, M. & Hortsman, M. The Management Trinity - One on Ones (Hall Of Fame Guidance). at https://www.manager-tools.com/2008/02/the-management-trinity-one-on-ones.