There are third party Ad-Tech companies that will sell IDFA - cookie combinations they have gathered from their "partners".
Think it through: you read this very article, and many cookies on that page you will have consented to will let many ad-tech companies know that you should probably be labeled "privacy conscious". Which, as any good AI will teach them, is closely related to the "extremist left" and "anti fascist" labels. Next, you start Youtube or Insta on your Apple device. Now you suddenly see promoted content from those bubbles because you probably want to click on it.