Some bloggers have experimented and used Mastodon as a medium to comments on their blog posts. Works quite well.

https://danielpecos.com/2022/12/25/mastodon-as-comment-system-for-your-static-blog/

It'd be super cool if we could connect article-hosting services with the power of activitypub or something but like one of those commenters mentioned, the issue would always be spam and security.

In my experience, the most readable response format are replys on some link aggregator (lemmy, hn, ...) and a link to that thread in the original post.

Doesn't ActivityPub kinda solve this? Now social media comments go directly to your blog's comments, it seems pretty ideal, don't even need to embed Mastodon or whatever. It's right there.