The Shared Storage API is a privacy-preserving web API to enable storage that is not partitioned by first-party site. Following Chrome's announcement that the current approach to third-party cookies will be maintained, we are now planning to deprecate and remove the Shared Storage API (along with certain other Privacy Sandbox APIs, as outlined on the Privacy Sandbox feature status page). [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 (currently at ~11% of page loads) as the main use cases for Shared Storage will remain possible in Chrome using third-party cookies. Further, other browser engines have not signaled interest in launching the API. See also the initial public proposal below.