HTTP2 is to hide connection latency by preloading. The other things are for bidirectional communication with a server. I would consider them very much apples

HTTP2 is to hide connection latency by preloading. The other things are for bidirectional communication with a server. I would consider them very much apples and oranges. Its not just that they are designed for different purposes; i don't think it is possible to even use server push for the purpose websockets is used for in the browser.