How is Discord more social than the other systems you mentioned? I consider something to be social (social media, social network, etc.) when the primary utility manifests as a function of establishing friends, followers, or whatever similar jargon.

That is: if the content presented to me is primarily generated by users who I've selected, while content generated by users I haven't selected is unavailable or relegated to lower tiers of functionality, then it's a social network/medium. In other words, it's the product of subscribing primarily to people (regardless of what they might discuss) rather than to topics (regardless of who participates).

I don't see Discord in this way. Isn't it more about subscribing to topics than to people?

I realize you're not speaking for yourself, but for the HN hivemind; my question remains.