Management surely encompasses the duties you have listed—bringing about improvement in employees. While I agree that certainly these duties involve a large portion of a manager’s overall job description, there are many other responsibilities not related to personnel that a manager takes on. I will share a few for you here.
Managers are usually responsible for stakeholder interactions. At a retail store, this might mean dealing with disgruntled customers. At a large corporation, this might look like reporting progress to the higher-ups or creating a long-term vision for the department.
Managers typically manage the budget or funding of an organization as well. Depending on the organization’s size, they may delegate these tasks to a finance employee or department.
Managers are responsible for implementing and monitoring policies and procedures. This could look like a standardized process for checking inventory or a safety procedure in a warehouse.
While the duties of a manger generally impact personnel in some way, it is not accurate to state that improving knowledge, skills, habits, and attitudes of employees is a manager’s sole duty.