@besendorf @delta which under the thread model "key gets leaked" is mostly irrelevant if you don't regularly delete your messages, because if your key gets leaked, it's likely that your device was compromised and the attacker can also read your stored messages (both incoming and outgoing).
Signal offers "disappearing messages", but not many people use it and many other chat apps don't offer similar features.
@crepererum @besendorf @delta I use disappearing messages all the time