Once you realize that the ability to update code, obviously, negates any advantage "end-to-end encryption" brings, or any other form of security, you'll quickly find there is not a single secure messenger.
This is an argument I've never been able to successfully make to anyone except a military colonel.
Is there really no way on an Android to keep an app forever without taking updates? Of course maybe the OS needs to be updated which then breaks the app and necessitates updating the app, but the distinction of a forced update seems important.
This is an argument I've never been able to successfully make to anyone except a military colonel.