I'm a bit sad that tls/http2 basically put the final nail in the coffin, essentially killing the viability (if not possibility) of elegant caching from REST. But arguably it's an architecture that's not needed with today's ample resources (fast networks, fast cpus, ample ram and storage).
Hard to imagine that the defining technology of this decade came out of a classic "screw standards; extend/embrace/extinguish"-playbook.
Thanks to Netscape/Mozilla/Firefox (and opera/chrome) it went the other way.. .