Not quite. In most companies managers are seen as 'inner circle' people while technologists are just workers. Managers get exposed to a lot more comms, giving more visibility and get ability to act like a smart person purely because they have more emails and get into more calls than the others. They not only get more power, but also get more info.
If you already don't know that though, are you really cut out to be a manager? You're joining the company "mafia", with all that implies, for good or ill.
I agree, and they have more power because they have more info and are given more visibility, and because they lack the deep technical knowledge in xyz, they compensate it with all sort of office politics.
Line level managers are the most easily replaceable and in my experience powerless people in an organization. When I was being hired as an IC in product companies before to lead major initiatives. One of my requirements was to report to either the director or CTO (startup). Even after the startup grew and they hired a EM, the CTO carved out a position for me so I wouldn’t report to an EM.