The claim I was rebutting was specifically about latency. Of course you can make a mess of it, no different than you can with request/response based protocols.

The claim I was rebutting was specifically about latency. Of course you can make a mess of it, no different than you can with request/response based protocols. On the other hand, you are going to struggle to implement bidirectional event based protocols without WebSockets that can be consumed by browser based clients or an application - WebSockets are very useful for that exact case, where you have a mixed client type consuming. It means you don’t need to offer web hooks and rest and some streaming protocol, you just have a WebSocket with some defined JSON message types without the rigmarole of distributing .proto or whatever.