What is your definition of a social network? In my view a social network requires that you actually represent social connections on the platform. Afaik there is no way for me to establish such a social connection with you on HN.
Explicit social connections are dying trend on social network, as weird as it sounds.
TikTok, Twitter's "For you", Reels - all of them are considered to be social networks, and they depend on algorithmic feeds recommending content to you.
Interesting point. Then I think we should acknowledge that former social networks are morphing into something that should no longer be called a social network?