Setting up a server and installing commenting software, and configuring OpenAuth etc login takes some time.

If you want to skip all that, you can use Effective Discussions embedded comments, demo: https://www.kajmagnus.blog/new-embedded-comments. It's open source (https://github.com/debiki/ed-server, I'm developing it), no ads, and has the features Schnack has (notifications via email) and some unique things people here at HN might like:

https://www.effectivediscussions.org/-32/how-hacker-news-can...

Go to https://www.effectivediscussions.org/ and click Create Forum and then choose Blog Comments if you want to try it out. (I hope some self promotion is ok.) It's also lightweight, just a 140 kb Javascript bundle.