The deeper background is of course Google's business model of data and privacy prostitution: Users give their private life to Google and they get web search, email, and videos back.

In a more reasonable world users would pay money for the services they want to use.

Of course it needs to be noted that most users don't even understand that they are selling themselves. And of the few who do most still think it's better than paying money.

This ruling, should Google comply in the end, will not change anything. Google will store the data in the EU and that's it. I don't think they share user data with the advertiser when they show an ad. So they could still show ads of US companies. And that's a niche business only anyway because when Europeans do business with Amazon, Disney, and the like they deal with the respective European subsidiaries already.