Many in the crypto and privacy community mistakenly trust Telegram because it’s “end to end encrypted”, but there are huge issues including not hiding the metadata, censorship, centralization, and phone numbers.
Send this video to your friend that asks why you won’t join:
https://video.simplifiedprivacy.com/why-telegram-sucks/
Why Matrix and not XMPP? XMPP is also flawed, but much less bloated, easier to selfhost and doesn’t have so many people being on central instance like matrix.org (there are other arguments as well).
Because there’s not a single good app for XMPP and nobody uses it.
Their bleeding edge app is Conversations which costs money (already unviable), and the app looks like it’s designed in 2012.
It does NOT cost money on F-Droid. You don’t even need to install the market itself, you can get the app from F-Droid’s website (though then you’d have to check for updates yourself). For me, it was a chance to get mom to F-droid.