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.
DuckDuckGo allows for supplement of Google Search, as does Brave, and other search engines. Google freaked out after the ChatGPT release (rightly so) and padded their hand a bit.
Impact would probably be Ads via Google Search Engine. Which, great, because Google Ads-generated results remain a huge vulnerability in terms of active phishing attacks. Maybe it's gotten better in the last month, however I don't really use Google Search anymore, to avoid phishing attacks.
And, this is one reason why I like Brave, because I can control what content cannot appear in my search results, to better mitigate phishing attacks.