Yes you depend on Apple's cooperation on iOS & Google's cooperation on Android. Even if you flash your phone with your own custom OS, your radio chips will stil

Yes you depend on Apple's cooperation on iOS & Google's cooperation on Android. Even if you flash your phone with your own custom OS, your radio chips will still run proprietary firmware that can be updated over the air without the OS even knowing. These aren't high priority problems right now for mass surveillance, as we have people using plain text chat. If you're expecting a wealthy adversary to directly target you, then the only safe move is to avoid technology.