Earlier quoted context omitted.
Fraud is probably a harder problem than discoverability. You can always exchange (maybe through an automated pairing) IPv6 addresses if nothing else. Supporting chargebacks, eliminating spam, blocking phishing, etc. if both harder and more important to a functioning culture.
Agreed. More broadly, decentralization is less equipped to counteract bad actors. You really are on your own, but isn't that what you asked for when you wanted to abandon Facebook/Google/government. A decentralized network cannot be trusted by nature. Anyone can join and lie. Successful decentralized networks need some cryptographically-secure checksum to verify its inputs: BitTorrent uses SHA-1; Bitcoin uses Merkle…
Edit: https://www.quora.com/Does-bittorrent-support-SHA-2-256-512-...