The OP statement was about insecurity that comes with signing code with anyone other than the owner.
It doesn't matter how secure communication between Apple and Apple device because even if it's perfect the owner is not secured from the Apple itself and those who Apple would love to communicate with. For instance oppressive governments. (here the result of such communication: blocked app that oppresive government didn't like https://apps.apple.com/us/app/%D0%BD%D0%B0%D0%B2%D0%B0%D0%BB...)
It doesn't matter how secure communication between Apple and Apple device because even if it's perfect the owner is not secured from the Apple itself and those who Apple would love to communicate with. For instance oppressive governments. (here the result of such communication: blocked app that oppresive government didn't like https://apps.apple.com/us/app/%D0%BD%D0%B0%D0%B2%D0%B0%D0%BB...)