> which means you can cache responses and send back 304s when the content doesn't change. Unless I misunderstand - that's still a round-trip to fetch and retur

> which means you can cache responses and send back 304s when the content doesn't change. Unless I misunderstand - that's still a round-trip to fetch and return a 304? Or are you thinking an edge cache closer to the end-user? (I don't disagree that websockets aren't a universal solution - but if used as server push - it's difficult to see how plain http could have lower latency? Long polling would be similar, but probably (even) harder to scale if you want 10k+ open connections?).