It is ridiculous. It's pretty much newspeak. Like calling installing applications "sideloading" when you're not using some megacorp's walled garden. Also, I'd say "HTML" not "HTTP". What's HTTP(/3) these days is not what HTTP(1.1) was in the past.

Discord "server".

The amount of ignorance of the newer generations it's astounding.

They keep reinventing the wheel over and over.

Depends on what exactly it is. If you for example take a react app that was doing rendering on user side and change it so that it is "pre-rendered" on the server it makes sense to call it server side rendering..

Ye ... I get flashbacks from coding jsp-pages in Java with FancyBeans.

It's called sending HTML from server.

aka a protocol for transferring hypertext from server

I get what are saying, basically all the MIME types of body is under the grand scheme of server side rendering. Fine.