I have discovered SimpleX Chat (nothing to do with XChat or HexChat, or the favorite letter of some dumb billionaire), and it appears being a legit good effort at providing good privacy while retaining "mainstream" usability.
And it has been audited (by one company so far, it seems).
The only concern I have is with regards to battery life (given that it has to maintain roughly as many open connections as you have contacts, AFAICT).
Totally agree. All of the comments in this thread are like "why not ____?". I can't event get a critical mass of contacts to use Signal. Adding more and more messaging apps just fractures people even more.