Browser do currently do this. H2 has two types of prioritisations: weighted, and dependency. All browsers implement weighted resource prioritisation and weigh

Browser do currently do this. H2 has two types of prioritisations: weighted, and dependency. All browsers implement weighted resource prioritisation and weigh resources by content type. This is a hold over from what they do for HTTP/1 connections. Firefox has dependency resources prioritisation. https://bitsup.blogspot.com.au/2015/01/http2-dependency-priorities-in-firefox.html https://bitsup.blogspot.com.au/2015/01/http2-dependency-prio... The spec purposely leave how these heuristics should work to the implementor. Things will change and implementations will diverge over time. The server ultimately being in control means we can tell the server what resources are important for specific pages with absolute knowledge of the page.