I'm using Matrix/element. I rather not give my phone number, you see, which is must-have for Signal. I have installed the app in my family's phones, and they were accepting, so all is well. I don't need to communicate through private messaging with anybody else, so who cares if others don't use matrix?

I've had good fortune converting some family and friends to use XMPP.

People always mention fragmentation, and while there is some truth to it, it can be massively minimised by choosing blessed clients and servers for them to use.

In my case, I run my own server, and thoroughly test the clients (especially the onboarding flow) that I expect them to use, so that any question they have, I can help them out with quickly. Since we're all on identically configured servers, it minimises one whole class of incompatibilities.

There is still unfortunately a bit of a usability gap compared to Signal - particularly on the iOS clients. But they have come a long way and are consistently improving.

Let's not forget that for those looking for alternatives, a key feature of signal is/was its SMS integration.

I use silence, a fork of signal.

• upside: it can still send and receive SMS messages!
• downside: nobody else uses it, so it only does SMS as a result.

What's your use case? Likeminded techie friends? Family members?

Signal works well as an alternative to the likes of Telegram and WhatsApp, even if it still requires a phone number and is centralised. Far easier to explain to the family instead of "oh well you can sign up on this website or this website or that website".

Granted, if you want to host a small Matrix server just for the family, then go for it.