I have no evidence but suspect most of the actual top 10% of managers are in the other 10%.
Quite simply, I'm more mentally drained at the end of a day working with AI than I am a normal day of coding. There is still a lot of energy and thought that needs to go into what needs to be written.
Anecdotally, I find the flow-vs-drained state is more about who uses the LLM and whether I'm in a position to know the difference between artifact and intent.
1. [Good] I know what I wanted, I have a concept of what "correct" looks like. I ask the LLM to do the thing, and I check if it's the thing I intended. Even if it's annoyingly wrong, I can fix it up.
2. [Bad] Someone else had a concept once. They put it through an LLM to generate something that reaches me, a ticket, PR, or review comment. However now I have to constantly guess which parts of the thing are "real" and which are nonsense the human never actually intended or even noticed.
The latter is worsened by how reading means inferring/simulate the mind of the writer, but LLM output is not from a mind we typically simulate. Subtle persistent wrongness is exhausting.