If you see something too bad or too good, you can send an email to the mods: firstname.lastname@example.org They usually reply soon, but it is a manual process, so use it wisely.
If you go to the  Algolia API, and filter "Comments in the last 24 hours". There's around 8,000 results. It's not really possible to keep track of that many comments and conversations (if he is a human that is).
My guess is that the moderation tools help him monitor for content that needs urgent attention, to keep the community and discussion healthy... so my final answer ~10% (1,000 comments per day)
All thanks to dang and sctb anyway. :)
Good, efficient moderation requires internal tooling and view development.