The Protected Audience API provides a method of interest-group advertising without third-party cookies or user tracking across sites. Following Chrome's announcement that the current approach to third-party cookies will be maintained, we are now planning to deprecate and remove the Protected Audience API (along with certain other Privacy Sandbox APIs, as outlined on the Privacy Sandbox feature status page).
Chrome has announced that the current approach to third-party cookies will be maintained. Since that announcement there has been virtually no interest in the Protected Audience API. Use of the joinAdInterestGroup() API has decreased by almost 100x and use of the runAdAuction() API has decreased by more than 10x. Of the auctions occurring today, virtually none of them have winners (determined by looking at the “Success” bucket count of the Ads.InterestGroup.Auction.Result UMA), implying that they are not providing useful benefit to the pages initiating them.