I certainly can moderate comments; I am the admin of the Mastodon server in question.
What wouldn’t work so well is to host comments on someone else’s Mastodon server, so it’s not a good fit for a low-tech/low-overhead site. There’s definitely a space for something with a lower barrier to entry, but I don’t think it fits well with the nonprofit, community-oriented approach to servers running most of the fediverse. Those users would be best served by a commercial subscription service.