I’m surprised the author did not mention NNTP, the protocol that ran the larges federated discussion system since 1986.
ActivityPub reinvented NNTP with less efficiency and very poor documentation.
makes me lose faith in Debian as an organisation
AFAIK this person has been also banned by FOSDEM and FSFE and others so I would take his statement with a pinch of salt before blaming Debian:
https://lwn.net/Articles/888204/ https://fsfe.org/about/legal/minutes/minutes-2019-10-12.en.pdf https://openlabs.cc/en/statement-we-have-been-a-target-of-disinformation-efforts-our-initial-reaction/
You just described what Briar is designed to do: multi-hop over WiFi and Bluetooth.
https://briarproject.org/ should be the most voted option. It works without Internet connection and even peer-to-peer over bluetooth.
5 years is way too short.