Agreed. May best to get family and close friends on Signal right away. Telegram is horribly unsecure.

If you are reffering to Signal then both app and server are open source. Just that the server is centralised.

For community building, try checking out SimpleX. Its open source and has an interesting take on anonynity. Plus it doesnt require phone numbers to create a user identity.

As for either being censorship resistant, I am unsure how we’ll they’d cope. But my guess is they would perform just fine in most scenarios.

Out of curiosity, why Matrix and not these other options:

• Jabber/XMPP - has a creat client called Conversations (decentralised)
• SimpleX - by far the most anonymous and potentially decent privacy (centralised server)
• Session - a Signal fork without requiring phone number

• all of the above are listed on F-Droid