Incompetent management is so commonplace in tech that it is practically a cliche. This example is how it's supposed to be in a healthy hierarchy.
It shows just how deeply imposters have infiltrated the industry. Somehow it has become conventional wisdom that people who are non-technical, or below average engineers, should manage the time of, and mentor engineers often much smarter, and more competent than them. That doesn't clear the bar of common sense.
There is value in having a hierarchy, some people are more competent, and better at planning, and time management, and interfacing with other people. Those people should be in charge of how other people spend their time. The confluence of those skills is rare. There are exponentially fewer people qualified to fill those roles than there are qualified to be engineers.
You shouldn't have managers unless you can find good ones. It is far better to spread management thin than to hire bad managers. You would never try to bring the quality of work, planning, and time management closer to that of a below average engineer, but that's exactly what happens when you bring in incompetent management.
It looks like Nvidia is doing it right. 40 is a high branching factor, and he can engage meaningfully with every one of them about their work.