There is a very large canyon between “good manager “ and “good leader,” especially in big tech. Many definitely do not cross pollinate.
Let’s not fool ourselves: the answer is obvious. The skills that make you a manager are not usually authentic leadership skills in a large corporation. That actual leader is a very special person with usually a very special set of circumstances inside a big company. Most simply optimize to survive and fill their coffers.
And don't forget the canyon between "average manager".
I've had about 15-20 managers in my career. 3 were bad enough I'd never work for them again. ~5 of them I'd enthusiastically work for again. 1 of them is truly a good leader that I've seen move mountains. The rest are forgettably average.
Your numbers sound like a normal distribution which makes sense. Would we expect all 20 to be in the 'move mountains' category? That wouldn't make sense.
Let’s not fool ourselves: the answer is obvious. The skills that make you a manager are not usually authentic leadership skills in a large corporation. That actual leader is a very special person with usually a very special set of circumstances inside a big company. Most simply optimize to survive and fill their coffers.