Google has eliminated 35% of managers overseeing small teams in past year

Around 5 is the correct number for a first line manager of a technical team. Go to 10 and it’s impossible to keep track of things. The day has only so many hours. Managing takes time.

For bigger teams (10+) you either need individuals who are very independent and driven, or have dependable line managers.

Every time I see manager with 5 people I know it will be daily 30m standups, friday “summary” meeting, weekly 1:1 and other nok work related activities. If team of 5 people need a babysitter fulltime it means there are no adults on that group.

No, 5 is about ideal. If you are micromanaging with that many people on your team then you are neglecting other aspects of being a manager. More than about 7 and you start being unavailable to your team when they need you, and won't have time to do the planning and process tasks.