Some of the most important work that a good manager does goes unseen by their team. I've been a manager and now I'm an IC so I've seen both sides. There is a lot of shielding and pushing back that managers do to protect their teams. Unless the manager tells their team about everything they've been doing behind the scenes, the team has no idea.
You say that you've never seen anything get done faster or better as a result of something a manager did but you've probably had managers that were working preventing interference, saying no to last minute requirement changes, pushing back on deadline changes, etc.
You say that you've never seen anything get done faster or better as a result of something a manager did but you've probably had managers that were working preventing interference, saying no to last minute requirement changes, pushing back on deadline changes, etc.