You still don't control what's installed on the device, which is the core problem behind owning an Apple device. You effectively don't own it, you only own the license to use it which can be revoked any time, remotely, by Apple.

Also can't change the IMEI as grandparent comment already mentioned, which means that the movement profile (aka your flat, your workplace, etc) is still there, everywhere, for governments to see. Can't really disable GSM/GPS module, because it is still active even when your phone is shut off.

Interesting. It is possible to disable GPS on Android. But yeah - cell towers will still know roughly where you are.