Okay back in the Don't Be Evil days, the business model expressed that no human should ever see private data except its owner. Google's business clients could ask Google questions about data analyses involving cross sections of thousands of users, but couldn't ask about individuals. Also you could tell Google to send ads to car owners (though normal Google advertising channels) and they would, and report how many users saw your ads.

Then two things became a problem.

One was internal affairs. Not just Google techs stalking their exes but people stealing databases of names and selling them to information collection orgs. So if you were a debt collector, it was good to have a friend in Google.

Also the PATRIOT act, FBI, DHS, NSA and eventually all of US law enforcement. Judges let them look at the raw Google data, which Google actually resisted with a high-powered legal team, but eventually the judges let law enforcement have at, which is how we have reverse warrants fulfilled by Google today.

In the aughts, Google was supposed to figure out a technological solution, so that the police could tap at the computer or look at the (salted) data all they want and without end user keys which no-one could access, they'd be SOL.

But they did too little too late, and nowadays, enough info on one person could narrow then down to a single human being, which John Oliver demonstrated a couple of years ago by building info kits on everyone in the US Senate, including acts of fraud and illicit affairs.

It was a good idea, and still may be if it's started locked down like Crystal Palace, but Google can't do it anymore.