Hey, there is now an Anarchism public group on Nostr. Nostr is a very simple protocol which aims to become the ultimate decentralized social network, already fulfilling functionality of Twitter, Reddit (not very advanced tho), Twitch, Telegram and more. It is also uncensorable.
It is also more anarchist than the fediverse because your identity there is not bound to a server/domain which can be shut down or moderated at any time.
To join the group, you have to search for this ID: nevent1qqs05w7vklg8ewh4g7u8rafp3dsvtcw3j7v9j4v7n4k5fxxewaggjdspp4mhxue69uhkummn9ekx7mqpz4mhxue69uhkummnw3ezuerpw3sju6rpw4esz9rhwden5te0dehhxarj9ehhsarj9ejx2assy2425
On Android the app Amethyst is very good. With Nostr, the client handles everything. The servers are just dumb relays which don’t need to be trusted. That’s why there are a lot of different clients. Each one is implementing different aspects of the protocol and they are always evolving.
If you want to have a peek at the group you can also check here: https://coracle.social/chat/note1lgaued7s0ja023acw86jrzmqchsar9uct92ea8tdgjvdja6s3ymqa579ar
EDIT: There are a LOT of Nostr resources available and you can decide how deep you want to dive into it. A very basic and easy introduction is https://usenostr.org/ . The devs website nostr.com also does a good job of getting the point across. There is an awesome list which can point you to any Nostr related resources like which clients to use and also what other introductory guides are availabe: https://github.com/aljazceru/awesome-nostr
Popular clients including web, desktop and mobile are also described here: https://nostr.com/clients
Note that Nostr is very decentralized and that some clients implement features which other clients don’t (yet).
This video can also show you visually how the relationship between clients and relays works: https://www.youtube.com/watch?v=yIccRIEr2gQ
Since you are using the term “anarchism” to describe principles that are rejected by the tradition from which the term arose, roughly one century and a half before its being appropriated by the movement with which you associate it, I would agree that others having a different philosophy than you is an accurate minimal characterization.