One of the biggest misconceptions in technology today is that "Google sells your data".
Google does not sell your data. Ever. The data Google openly and transparently collects about you forms very core of Google's business - they would be stupid to sell it. Your data is safer at Google than on any other (connected) computer in the world, including your own.
Google sells ad spots, not user data.
What we know is that they sell at least a part of our metadata to advertisers. Until GDPR, any user of Google Analytics could see your IP and what you did in his site in a very detailed way. If they give that to you for free (well, they get that data for themselves, but still), I wonder what are they giving to paying advertisers.
You are right. Google Analytics doesn't give web admins any data they couldn't get by themselves. It only makes it way easier, enough to make it practical/affordable for people who wouldn't go so far otherwise. Sorry, I should have been more accurate.
I see your point: Google is not nearly as bad as Facebook/Meta and the others. They only sell aggregate metadata, which is bad enough, but not Facebook bad.