Define the manager role
Most organisations have no idea what managers are supposed to do. Try asking "What is the manager role?" and "How do we expect managers to spend their time?" - how clear are the answers? Are they written down? Do people across the organisation agree with them? Do they reflect what is happening in practice?
Good managers can do so much! They can bring clarity to their team. They can clear away obstacles. They can improve the way the work works. They can coach their team to become more able to solve more problems for themselves - but to do all these things takes time. It is not viable as a side hustle.
For years I have been asking groups of people in this job, "What happened the day you became a manager?" The response is almost always the same: puzzled looks, then shrugs, and finally comments such as "Nothing." You are supposed to figure it out for yourself, like sex, I suppose, usually with equivalently dire initial consequences. Yesterday you were playing the flute or doing surgery; today you find yourself managing people who are doing these things. Everything has changed. Yet you are on your own, confused.
Managing by Henry Mintzberg (2009)
I had a conversation recently in which someone asked me what I think the biggest operations pitfall is in scale-ups... my answer: getting management wrong. Management is an activity that people need time to do - if you load your manager roles up with loads of other responsibilities, where is their time to work on the system of the work? How will they be available to their reports when they're needed to help them get unstuck? When will they be able to "go and see"?