That’s the thing. No tracking occurs. And no personal data is collected or sent anywhere. It stays in your browser. In a way it’s like your browser history. The browser knows your interests and runs auctions for advertisers. And as per GDPR you can review it, correct it and opt out at any time. It’s basically the same horrible adware thing but without tracking and fully compliant with all EU laws.
At some point Google will turn off 3rd party cookies (a decade after Safari) and adtech will have no choice but to adopt their stuff. By end of 2024 if all goes according to plan.