If you don't trust the other end then disappearing messages should be used, simple.
This is one of the problems with Signal having a bit of confusion about what exactly it's use-case is. There are plenty of cases where locking down the ability to save/view/export messages are valuable, and Signal provides tools to be able to do that. Making that the mandatory case though means that it's harder to adopt as a general-purpose communication platform.
The need to decide if the goal is still to get as many people off of SMS/facebook-messenger as possible, or if the goal is to provide extreme security to dissidents and protestors, or if they're going to spend the effort to be able to do both effectively and let you choose which conversations or messages get which level of protection.
This is one of the problems with Signal having a bit of confusion about what exactly it's use-case is. There are plenty of cases where locking down the ability to save/view/export messages are valuable, and Signal provides tools to be able to do that. Making that the mandatory case though means that it's harder to adopt as a general-purpose communication platform.
The need to decide if the goal is still to get as many people off of SMS/facebook-messenger as possible, or if the goal is to provide extreme security to dissidents and protestors, or if they're going to spend the effort to be able to do both effectively and let you choose which conversations or messages get which level of protection.