You'll also notice that I use WebMentions to import those 3rd party discussions (or links to them) into my blog.
That way users aren't subject to the advertising on platform A, the poor moderation on platform B, or the difficulty of even finding the comments on platform C.
I'm trying Mastodon comments on my own blog, that I'm not posting here because it isn't really ready, from my own Mastodon account. I'd never even consider public comments anymore, it just seems like inviting trouble.