These things are rather pointless, as one could always use a standalone encryption app, and copy&paste text to and from a non encrypted chat app. i.e. how one

These things are rather pointless, as one could always use a standalone encryption app, and copy&paste text to and from a non encrypted chat app. i.e. how one originally made use of PGP. The difficulty which PGP had of key exchange could be handled somewhat like Signal does now, via a personal physical sync of the phones. At which point, the authorities will still be able to make use of "traffic analysis" as they always have. So they'll be able to tell which parties are communicating, but not what is being said.