The Attribution Reporting API is a privacy-preserving web API designed to measure ad conversions 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 Attribution Reporting API (along with other Privacy Sandbox APIs). [0]: https://privacysandbox.com/news/privacy-sandbox-next-steps/
Chrome has announced that the current approach to third-party cookies will be maintained. Given this, we expect adoption to decrease over time as cross-site measurement will remain possible in Chrome using third-party cookies. Further, other browser engines have not signaled interest in launching the API. Removing this (and other Privacy Sandbox APIs) will help focus efforts on the proposed interoperable Attribution standard. See also https://privacysandbox.com/news/update-on-plans-for-privacy-sandbox-technologies/.