The content you’ve linked really does a good job at showing how completely decentralized P2P social media is a terrible, terrible idea.
A big internet forum like HN gets tons of crap comments. Most eventually get moderated, but not all; and even the ones that get moderated take time before we see them.
P2P social media is a fantastic idea.
The quality of Reddit is created by the users. If they used a P2P platform the content would be of high quality.