I'm surprised that this article didn't consider HTTP/2 or QUIC at all. In either case, the disadvantages of polling are dramatically decreased (persistent conne

I'm surprised that this article didn't consider HTTP/2 or QUIC at all. In either case, the disadvantages of polling are dramatically decreased (persistent connection or lack of need for one, header compression, etc.). Having long-lived connections with web sockets is hard to do at scale (pinning a user to a single server, pushing caching down a layer or two in the stack), and when you're Google the back-end efficiency of stateless requests is hardly a concern. If you're on a browser that doesn't support a new version of HTTP, you're probably also not able to use web sockets. Supporting two dedicated transports (one for fallback, one for marginal efficiency gains over the fallback) for a small feature like this seems crazy.