[KajMagnus]

There's also EffectiveDiscussions (https://www.effectivediscussions.org), which doesn't have any of those drawbacks. It has email+password login, Gmail, FB, GitHub. Open source, and hosted too, if you don't want to provision your own server.

Demo: https://www.kajmagnus.blog/new-embedded-comments

It has improvements over Disqus and HackerNews: https://www.effectivediscussions.org/-32/how-hacker-news-can.... GitHub: https://github.com/debiki/ed-server. (I'm developing it.)