I think I’m going to skip the comment feature for fx (https://fx.huijzer.xyz). Niall Ferguson recently argued that people in technology often forget about the past and say that now everything is different even though usually it isn’t (https://youtu.be/giZC4pCqB4o). Most of the time, new things are just old things with slight variations.
So what are old things that are great? Publishing text from one paragraph length to multiple paragraphs. This is what newspapers did for more than a century. Then you still have book authors and authors like Dijkstra (EWD notes) that also published. To write a comment, you have to write your own publication. Not some effortless comment a la modern social media.
Thinking about comments in general, the main problems I see is that they are often abused for marketing/spam, see X. This doesn’t add value to the reader. Most other comments are written after about 3 seconds of thought.
Like how often do you see a great discussion or article and then a thoughtful comment that adds a valid point? On most social media I never. Apart from Hacker News, Lobsters, or maybe Reddit. Most comments are usually jokes.
Then there is also the fact that for good writing it’s probably good to not get too much direct feedback. There is something to be said to have some space. Comments might negatively impact the writing quality since the author will try to appease the commenters. Being too aware of comments can negatively impact writing see eg https://ashley.dev/posts/fear-of-being-seen/.
Then there is also the problem of responsibility. If my site shows your comment, I’m kind of responsible for your text. It’s a mess. It’s better if you just post on your site or send an email.
And if an author wants feedback, the author can post the article to one of the many social media sites such as Reddit, Lobsters, LinkedIn, or Mastodon to interact with readers there. I’ve seen many writers do this successfully. (EDIT: This is called the POSSE model Publish (on your) Own Site, Syndicate Elsewhere. Thanks to KrazyKirby99999 on Reddit.)
So long story short, if I look through places of great writing, they usually didn’t allow random people to write something below the text. See EWD, Paul Graham’s essays, Seth Godin’s blog, and Cal Newport's blog and books. Joe Rogan even adviced Lex Fridman to never read the comments IIRC.