Although it has better implementation status than HTTP/3 server push, it remains of limited use, with adoption numbers seen as negligible. Per IETF 102 materials, server push was used only in 0.04% of sessions. It was considered to be "difficult to use effectively" in RFC 9113. Its use is further limited by badly matching to fetch/cache/connection models in browsers, see related discussions linked from [1].

[nginx] HTTP/2: removed server push (ticket #2432). https://forum.nginx.org/read.php?29,297497

[1] https://jakearchibald.com/2017/h2-push-tougher-than-i-thought/