I don't think most users expect their chat app to be protected if the police seize their phone. The main concern is about intercepting messages between 2 parti

I don't think most users expect their chat app to be protected if the police seize their phone. The main concern is about intercepting messages between 2 parties or mass exploiting the history stored by the provider. Sure, for some case, it can be important, but that's a much more difficult and rare threat model to address.