HTTP is overly verbose, is a pain and slow to parse, and there are various interpretations of what the protocol spec allows and disallows. If machines are communicating why should it be in a human readable format? Binary is far quicker
If, in the unlikely case that your particular bit of brilliance is indeed hampered by the vestigial amount of overhead still present in contemporary HTTP, then you might do as Google and several other operations have done and dispense with traditional techniques (including TCP) altogether via QUIC.
Just because what you see in the Network tab of your browser's 'Developer tools' window looks like something from 2005 doesn't mean that's what is actually on the wire. It mostly isn't any longer as a share of global traffic.
But again, all of that is irrelevant; the post provided no evidence that replacing HTTP with some dubiously unnamed form of RPC would solve any actual problems. HTTP was tossed in the rant basket with a bunch of other things, few of which appeared relevant to the actual failure modes cited.
[1] https://www.oreilly.com/library/view/high-performance-browse... [2] https://github.com/http2/http2-spec/wiki/Implementations
Thanks for the list of HTTP/2 implementations. I hope they all interpret the spec the same and so can all be used with each other.