client-side rendering was coined because server-side rendering was the default.
now that client-side rendering is ubiquitous, being explicit about server-side rending became necessary and along lost in translation became "technique" - is what I think happened here.
Probably too late to change now, but I wish the term ‘rendering’ wasn’t used to describe completely different things.
Server side rendering is about dynamically generating HTML code. Client side rendering generates DOM objects in memory, and only rarely generates HTML strings. And then there’s actual rendering, which generates pixels on a display.
People who aren’t familiar with web development often conflate these concepts.