@mntmn I tried Matrix for a bicycle chat group but somehow the whole client / notification thing was not for me. I dropped it after 2 weeks. Also, I think it’s already hard to convince friends & family to use Signal instead of WhatsApp. And that's with Signal being so similar to WhatsApp. Matrix IMHO is too different from what people are used to.

@mntmn
For me, the only thing that passed the UX test for my elderly mother was Threema.

I find I really enjoy it in usage, and I can at least backup everyone's profile/keys to my NextCloud automatically, but not messages/media (yet).

Had I my own email server at that decision time, ArcaneChat/DeltaChat might have been it, despite the much smaller max filesize.

@mntmn If i understand you correctly then xmpp might do the job. https://xmpp.org/
Matrix might be a better Telegram/Discord equivalent.
Xmpp is probably a good Signal equivalent.

I like Signal a lot because of the ease of use

@mntmn If you don't need it for giga groups, honestly give Delta Chat a try. Very nice WhatsApp/Telegram/Signal like UI (I'm biased, developed parts of it).
- It's based on E-Mail, so it's federated & self hosting is easy, but one can simply use posteo/riseup/systemli etc.
- All major platforms are supported, there's even a client for ubuntu touch
- It's using Autocrypt for encryption which is trust on first use pgp. You can scan QR codes to verify keys. It got security audited multiple times.
- Groups work really well and are also e2ee, saw groups with 50+ people and no problems. People can join via a link/qr code or simply be added. There's no permission system, so everyones "admin" which is anyways good for family/friend groups.
- Support for voice messages/images/videos/reactions etc, you can even have little apps for shared shopping lists/polls which are basically little sandboxed html/js apps
- Of course open source, funding received through OTF/NLNet/Prototype Fund, no VC

@mntmn why not Xmpp ?