> absolute total autonomy and ownership of their conversations, because the only place their conversations exist is on the devices they own.
This also means a total loss of data if something happens to the device.
Of course, I can imagine some usecases where this would be a plus, but I suspect that most of them are on the wrong side of the law. Now, coming from Russia, I know that it doesn't automatically mean it is something bad, but still, in vast majority of cases, it does.
Not my cup of tea, thanks, because keeping my data is very important for me. For this, good old federated model with client-server architecture strikes the best balance between reliability and privacy. Just use your own domain name, and all will be fine