I've gone back and forth about whether or not to have comments on the site. Most of all, I've liked having absolutely no server or external scripts on the site, and not having to moderate comments that are publicly facing on the site.
A bit ago, I implemented my own comments REST API server with Node and wrote about it here, which was awesome, but I didn't implement any user system or authentication, so the barrier to posting was just too low.
I couldn't keep ignoring how awesome Utterances looks, an open source project by Jeremy Danyow. Not only does it look absolutely fantastic, but it took me about 15 minutes to set up completely on my Gatsby site.
I made a comments repo to host all the issues and responses. Connecting to the Utterances GitHub app is required to leave a comment through the site, though you can also comment directly through GitHub if the issue exists. I imagine spam and obnoxious comments will be much more rare through this system, and people will actually be able to participate in discussions and leave helpful comments once again.