To those who would say "but people would be manipulated into installing malware".

Firstly, Apple could make the unlocking process purposely hard. Many Android phones come with unlockable bootloaders, but the average person has no idea because you need a computer with the SDK to run that specific command to unlock it.

Secondly, people do get scammed on iOS devices anyway. Both through the web, and through poorly reviewed apps that slip to the app store every now and then. Moreover, Apple has a vested interest in not policing these thoroughly because they get to keep the 30% cut from the scammers' earnings.