This is a categorically false premise. The kind of statement that only makes sense when you're in a deep bubble and entirely removed from the average person's use of the internet.
Deliberately removing yourself from Google is fine for the author who is more concerned about taking an ideological stance than they are about being discoverable, but removing yourself from Google is terribly bad advice for anyone who wants to help people find their content.
Many people do use Google to find content and people, even if you don't.
I'm not convinced, though accept that this could be because I am in that bubble.
I can't imagine this average person searching for me on Google, finding nothing (which they won't, because I did the same as the author long ago), and concluding that there is nothing to find. Especially since nobody who has tried to find information about me after real life encounters has stopped at Google.
The more persistent ones did eventual find bits and pieces, but admittedly they were more technically inclined. Even so, none of them — technical or not — presumed that there _wasn't_ anything to find.