I've never moved the goalposts. I've held the entire time that social media is a platform for sharing the ongoings of your life with friends or public via a single post.

By your definition, writing your phone number on a bathroom stall is social media. By your definition, literally every single account based service on the Internet is social media.

A term should mean something. It shouldn't just be a fancy team for "oh, you know, everything ever"