Comment by immibis

These things can still be used as evidence. The process used by the police of a rogue country (or any other adversary) isn't a cryptographer's highly technical wet dream or nightmare. They simply look at the screen of your phone saying you sent or received a message, and as far as the adversary is concerned, that proves you sent or received it. Even if you didn't. (Actually, they use Cellebrite and just trust whatever the Cellebrite analyzer outputs, which is basically what your screen would have said)

I've yet to see a protocol that lets you convincingly insert fake messages into both sides of your own chat history, especially in a way that isn't detectable by say, sqlite rowid order, but that would be an interesting idea for where to take this sort of thing.