The GDPR argument is a bit moot because Scuttlebutt is no different than sharing pictures in gossip style (a.k.a. memes). If one of your childhood pictures happens to become the new meme, there's little hope that GDPR enforcement would suffice to de facto delete it from the internet: from Reddit, from Imgur, from independent websites, from Torrent, etc. The same is with Scuttlebutt, but data is primarily shared between friends without contracts, not from people to a particular company. GDPR applies to institutions.

The other points are just stating "much harder", which seems to just bring skepticism and little actionable suggestions.