OMEMO actually implemented the double-ratchet algorithm developed as part of the Signal Protocol. Signal, in my eyes, is still the benchmark for balance between usability and security. That's fine if you prefer XMPP w/ OMEMO, and it's arguably just as secure.

...but it's unfair to call Signal another IM silo that's "hostile" towards other clients. Signal is 100% open source, along with the Signal Protocol which powers it all. It is community supported and wholly dedicated to brining cryptography to everybody. The latest implementation of OMEMO as it exists today would not be what it is without Signal.

Sure, Signal contributed back to the whole IM scene some very useful things, I'm grateful for that. That still won't make me use or recommend their network, as they actively request alternative clients to stop using their servers and are just yet another, centralized network that can just go away at any moment.

In Poland I don't see many people using Signal yet. I'm recommending Conversations to anyone who asks, which doesn't seem far away in terms of usability. On desktop it's a bit worse (I mean, I'm very comfy with my Psi, but wouldn't recommend it to a random person on the street), however Dino looks very promising and might fill that niche soon.

A relevant blogpost by Moxie about why the Signal app uses a centralized model (and thus doesn't allow other apps to connect to their servers): https://signal.org/blog/the-ecosystem-is-moving/

Still all code is open source and Signal's code does support federation. Moxie stated before that you can take the code and start a federated version of Signal if you want.

Of course you can. That won't be Signal though, just an another network using its code, and there's already XMPP, so there's no need for that.

> (and thus doesn't allow other apps to connect to their servers)

"thus"? You can easily use centralized model and allow the client ecosystem to thrive. You don't have to do much, just don't actively prohibit them.

And I know the blog post, it isn't very convincing.

As soon as I saw the Signal client was a web browser disguised as a desktop application, I have expected the discovery of similar issues. But as I only use Signal as an upgraded version of Plain Old Telephone for secure communication of the common people (I guess this is why the OP said "you should", not as an attack to other chats, because it serves a purpose), only talk to those people who knew my personal phone number, I didn't worry it too much. For other communications, I use PGP+E-mail, OTR/OMEMO+XMPP, IRC, Matrix, etc.

I agree with you that OMEMO + XMPP is much preferred, however the on boarding process for that is significantly more challenging compared to Signal (Download App, Start Messaging). I've managed to get a fair amount of my friends and family to go the Signal route. It's a compromise, but one that I'll live with for now.

Encrypted Open Source Messaging > Non-encrypted messaging