Sure. Go and have a look at GSM and friends. I’d say the cellular network in general is routinely being manipulated. The protocols and standards for over-the-air are demonstrably insecure and assuming the actual hardware is also insecure is reasonable as well.
Part of the point of this thread is that 'modern flagship phones' are designed with problems like that in mind. You're the one claiming to have 'proof' they are trivially insecure.
I pointed at the lack of source code as a starting point for proof of complete insecurity. I pointed at the ease of the existing protocols in active use as an example of that insecurity. That insecurity is the basis for Stingray fake towers. If you can fake the tower then the cellular modules can’t be much better.
I’m sure various agencies are quite frustrated by their inability to use the cellular modem as an entry point into Apple’s phones. That by itself is another pointer.
