neowin[.]net/guides/google-chrome-moves-forward-with-its-targeted-ad-tracking-system-heres-how-to-turn-it-off/
Google first came up with Federated Learning of Cohorts (FLoC), which allowed Google to share individual data with advertisers. Everyone hated it, so now Google's rolling out their Topics API, which tracks the topics of the sites you visit in an attempt to gauge your interests. The linked article shows how / where to turn it off in Chrome's settings if/when it goes live for you. Early today I checked and it was off -- checking just now it had been turned on.