Uhm.. I have a very low Slashdot ID number, so I saw that site develop from its start (19 years ago). Back then it was what HN is now. They have those things. It has become unreadable and unusable (has been for years now) - the most idiotic and trite one-sentence statement is tagged "insightful" if it the visiting crowds like it (which happens a lot). Go and see for yourself, if you dare: https://slashdot.org/

Example - and I clicked exactly once on a headline and selected the very first comment tagged "Insightful", so I made no attempt to find an example that fits my narrative:

  Win 10 is good OS that would be quickly adopted if/when MS
  decided to remove or make optional bolted-on telemetry
  malware. Such "feature" is simply not acceptable on a non-free 
  product.

That's it, that's the entire statement. I have to add, for those who don't know the site, only a few people have mod points at any given time (you get 5 or 15, distributed randomly after an internal algorithm giving the active users more and more often), so they are precious. Less than 10% of articles are tagged at all for an average topic, so one would expect the ones marked "Insightful" or "Interesting" to actually be just that.

If you now think "They need meta-moderation, moderation of the moderators! This should improve quality!" - well, I'm sorry to tell you they've had just that for ages...

So simply implementing any mechanism in software is not sufficient. There is no magic algorithm or method, thus far anything someone tried eventually deteriorated. I must say reddit is actually doing surprisingly well, mostly because they managed to have "sites with in the site" with their individually managed subreddits.