This site is a social network. Not as bad as Facebook or Twitter/X, but pretty much the same idea.
It's a forum... And a bloody good one.
It's precisely those differences that matter: the highly polished, short form content designed to give a dopamine hit. The highly polarized topics, the hot takes, ML echo chambers, dark patterns, all of it.
HN isn't without its issues, and much of those other platforms' issues bleed over, but we're talking apples and aircraft carriers here, and I reject the idea that this is "pretty much the same thing".