I agree with you. His books on JavaScript are really great. They treat JavaScript as a first class programming language and not a scripting language and teach you from first principles without naming any of the bad actors in the JavaScript world and no biases. His Books are amazingly well written. I too am surprised how less he was paid compared to what I believe would be his calibre.

The other interpretation would be that the absurd salaries that we hear of are the outliers and most very good engineers flatten out at around 200K USD