It’s fundamentally about trust models. That is to say, about the audience.
Everybody gave up trusting webrings because Google provided better results. Now that Google results are shit, there’s room for other information vendors to come along, even if it’s in narrow areas.
Actually, HN is already this for me in some respects.
In my opinion this site is not really so different from, say, Reddit, beyond having more focused rules and being smaller. So I don't think my idea that social media have supplanted the Web ring is wide of the mark.