Google is planning to remove support
for HTTP/2 server push from Chrome.
I once spent quite a long time getting Blackbird
to support server push. It works: it would send the one critical CSS file needed using server push, but it was a pain to implement and ultimately saved maybe 5 ms.
For most sites, it's not really worth it. And Google's data seemed to show that: 99.95% of requests didn't include a server push. In a way, it's kind of a shame because it could be a useful tool for web performance in the right situation. It's just that those situations are extremely rare.