There is some truth to the idea and most skills have a hierarchy/normal distribution/metrics/quality ranking that reveals partial insight into one's output.

John Carmack is definitely 10x or 100x (or 1000x) compared to me on low-level graphics programming, just factually, not that it says much about either of us.

But the '10x programmer' idea is soaking up and refueling some fanaticism. Let's all double down on the concept of high performance, for no particular reason we can agree on.