At this moment, with the enormous stir around biased whatsapp and the like, there is no doubt the end2end encrypted Signal is definitely and safely started, with a strongly growing mass of users ensuring the critical mass is reached too.
Then the next step is (again) to prepare a switch towards similarly open-source apps, end2end encrypted, but that will additionally eliminate the last criticality : the risk that someone, or some state, stops the central server.
Signal still needs a server.
Jami doesn't, and is a very efficient candidate for this next step.
It already offers almost every end-user wish, from multi-chat video to attachments.
His present drawbacks are two :
(1) far, far less users, so the critical mass is just not reached, and
(2) 'no central server' means no intermediate storage at all. In other words, for your message to reach me, both you and me MUST be online. At the same time.
This may appear minor to 'permanent' smartphone users, but Jami also runs on computers, and these users will probably be pissed off.
So, ... let's touch wood, as they say...