I’ve been inspecting this topic quite a lot and I’m a little confused now. So, we have reasons not to use Signal, reasons not to use Matrix, there were also some claims about Session being a fraught. Briar is mostly activists related (not very suitable for daily use), XMPP lacks good clients and suffers from fragmentation of protocol implementation, SimpleX is too feature-incomplete (no UnifiedPush support, big battery drain on Android, very decent desktop client without any message sync). I can’t say a lot about Threema or Wire, as I’m not very familiar with them.
So, my question is — is there any good private messenger at all? What do you think is the most acceptable option?
DeltaChat. I don’t use it myself because it’s built on electron (which basically excludes 99% of modern chat clients); but as it’s technically an email client turned into a chat client, we can assume you’re protected by PGP when writing to most users, and with the added effect of not needing to convince anyone to install anything since from their end it’s just an email.