I couldn't find another online platform around topics that interest me that's simple enough to join and participate as Reddit (Stack Overflow comes close, but is also one of the most abrupt social networks out there). I rarely engage in commenting, but I do submit & read quite a bit of content in the channels I follow.
old.reddit.com is still the best format, in my opinion. Like HN, keeping it simple and focused on the content instead of the users will ensure to some degree that the right type of public will be interested to spend time around there. This, I suspect, is where almost every other social platform fails and becomes perishable. And probably desperate monetisation efforts, like Quora.
As with every social platform, the more popular it becomes, the more often you find low quality content and users trying to take advantage of the traffic or business generation potential offered by the platform.
LE: typos & suggested channels.
Channels I can recommend (though some are quite niched)
- r/AbandonedPorn/ (images)
- r/AcademicPhilosophy/
- r/Archivists/
- r/bestof/ (arguably best user comments)
- r/indepthstories/ (long form articles)
- r/longform/ (long form articles)
- r/Longreads/ (long form articles)
- r/TrueReddit/ (long form articles)
- r/privacytoolsIO/
- r/selfhosted/
- r/stopworking/