We really should consider services that are not #ActivityPub based but still a federated to be part of the #Fediverse and promote them accordingly. Self-hosting is a plus.
#Usenet is also federated and has been since 1979! There are free providers: https://www.big-8.org/wiki/News_service_providers. If one excludes binaries groups, it's possible to peer with other providers via #NNTP. Posts and groups are linkable in HTML.
