Comment by cowlevel
16 hours ago
Web uses web protocols, notweb uses notweb protocols. When I write an XMPP bot it has to speak XMPP, not HTTP. I could write my video game server to use XMPP but why the heck would I do that? If I choose a badly fitting protocol, it's on me.
I think one problem there is that a lot of places block other ports. Was that not why websockets runs on http ports?
Websockets have to be careful not to enable a client-side SSRF by accessing anything you couldn't already access with an <img> tag. They can use any port except the ones that are generally prohibited for browser HTTP requests, such as 25 and 6667.