[simmervigor]

Co-chair of the QUIC WG here. Early in the process, we decided it was important that HTTP/3 provide parity with HTTP/2. That helps application developers to migrate back and forth between versions with less friction. So we include features of bidirectional stream multiplexing, request/response stream cancellation, server push, header compression, and graceful connection closure.

Some of those are more optional than others i.e. Server Push. Whether implementations choose to support a feature or not, at least the IETF maintain the close parity at the protocol level.

Stream prioritization is a different matter. That was very tricky in HTTP/3 [1], and through the process we designed Extensible Priorities, which is simpler and works over both H2 and H3. That was published today also as RFC 9218[2].

[1] https://blog.cloudflare.com/adopting-a-new-approach-to-http-...

[2] https://www.rfc-editor.org/info/rfc9218

Edit: typo fix