Google is an advertising company, but that's not the main reason for their privacy sandbox and it's ad-friendly features. Google needs the open web to survive as a search provider. If everything turns into a paywall or cookie/privacy wall then Google can't index that content. They already can't see the content on Facebook and Twitter.

Google makes most of their money from search ads -- I've heard upwards of 80% -- and search ads supposedly don't even use targeting information.