yeah, but we're talking about what website operators can do to speed up their site. you can try to dramatically reduce the number of files you need to send. OR, you can just enable HTTP2. HTTP2 seems like a more simple answer.
HTTP2 doesn't magically change the number of hosts you communicate with (CDNs, ad networks, tracking providers, etc) and most importantly, it doesn't reduce the amount of shit developers are piling onto web pages.