I mean, sure, there were "web pages being rendered on the server" back in the day. But that was the rule, and there was no name for it. Wikipedia's SSR page us

I mean, sure, there were "web pages being rendered on the server" back in the day. But that was the rule, and there was no name for it. Wikipedia's SSR page used to be called "Server Side Scripting", which is kind of a misnomer, and is very generic. That would also include serving JSON from the backend... and "scripting" not only limited in scope but also non-ambiguous. So, someone had to invent a term. The name "Server Side Rendering" is quite good actually, it describes what's actually happening rather than being some random buzzword. (Of course, there will be people claiming "ackshually SSR is only when a Next.js-like-framework does it", but that was never agreed upon by the majority of devs)