If your manager has no power to decide what you work on, who gets promoted, what deadlines you should have, who is to blame when things go wrong, who to fire et

If your manager has no power to decide what you work on, who gets promoted, what deadlines you should have, who is to blame when things go wrong, who to fire etc, then sure he doesn't need to be technical. Otherwise he will just promote and listen to the popular guys and fire the unpopular ones.