As Ciro started getting a lot of comments on his home page about China, he decided that Disqus does not scale, and that it would be more productive long term to remove it and point people to GitHub issues instead.

Upsides of removal:

Disqus discoverability is bad:
- there is no decent way to search existing issues, you have to do JavaScript infinite loading + Ctrl + F. So every reply that he wrote is a waste of time, as it will never be seen again.
- comments don't have: decent URLs, titles, metadata like tags or open / close
Disqus archival is bad: web.archive.org/ does not work, and no one knows how to export the issues: www.archiveteam.org/index.php?title=Disqus
before, there were two places where people could comment, Disqus and GitHub issues. Now there is just one.
Disqus has ads if you ever reach enough traffic, which unacceptable, especially if the website owner don't get paid for them! It also makes page loads slower, although that likely does not matter much.

Downsides:

people are more likely to comment on Disqus than to create an issue on GitHub, especially because most people use GitHub professionally. But this has the upside that there will be less shitposts as well.
with Disqus you can see all issues attached to a page automatically, which is nice. But for as long as Ciro is alive, he intends to just solve the issues, cross link between content and issues and tag things appropriately.