You can change the free parts of Android. That's why everyone and their brother can release Android phones, not just Google, and why F-Droid and Replicant can e

You can change the free parts of Android. That's why everyone and their brother can release Android phones, not just Google, and why F-Droid and Replicant can exist. However, I think you may be correct that some or perhaps most Android hardware is tivoised to not allow you to install derivative Androids. If so, that's a case of what good is a phone call, Mr Anderson, if you cannot speak.