I’ve interviewed more than a handful of extremely accomplished people with decades of experience as developers and then engineering managers who couldn’t answer extremely basic coding questions (we’re talking “efficiently find duplicates in a list” or “compute Fibonacci numbers” basic). These people never could get past the O(n^2) brute force solution for finding duplicates (or the brute force compute every Fibonacci number starting from 1, 1), because they hadn’t thought about even basic algorithmic complexity in so long. And when people like this are giving orders from the top, you can see how software can get so slow.
I have no doubt that when these people were actually still coding, they could have answered my questions in their sleep. Quitting coding for engineering management really does one a disservice IMO. To this article’s point, I’ve also had the pleasure of working with people with decades of experience who never quit coding even as senior managers and their level of competence and productivity is astounding.