Every forum I can remember shows the most popular threads first. Even 4chan does that with thread bumping, the most engaged-with threads sort to the top. Given the hyperbole of the times, that counts as "finely tuning their addictive homepage feed."
Hacker News, like Reddit, is both a forum and a link aggregator. It has features which are designed to influence you and to be addictive. And I promise you that people are as addicted to HN as others are to Facebook, Twitter, TikTok etc.
That's what I meant too. PHPBB forums and the like had plenty of features that would be considered "addictive" in the modern climate, as well as "algorithmic" feeds.
They certainly could be categorized the same way. I don't think they will only because the political will isn't there and such forums aren't popular enough to matter. But if regulation of social media causes those forums to resurge in popularity then that might change.
This is a social media news feed-style website. Like Reddit, or old Digg.