No, I don’t think so. Not in the sense that social media became defined. Web forum, and bbs rooms, existed long before the term. The key difference and turning point was self promotion, and the removal of anonymity. I know they are similar and overlap, but the evolution from one to the other did occur. Reddit and Lemmy still have more in common with news aggregation and forums than say a Titter, Instagram, Facebook, or TikTok. Most of the content here is in reference to something else, end then discussion are on that.
If you look up the history of the term the turning point is definitely the change to having real personas and real people connect. That is where the “social” part comes from. The term “social networking”. But we are not social networking here. Do you actually know anyone here? Do you want to?