Also many frequency bands that modern phones use are regulated, especially heavily with LTE and later due to mixings with the military and public service freque

Also many frequency bands that modern phones use are regulated, especially heavily with LTE and later due to mixings with the military and public service frequencies. The baseband chips have modifiable software that can be stored in the same flash memory. The companies are trying to avoid the blame by creating a paper trail, if someone modifies a phone to illegally broadcast protected frequencies.