Not so sure I agree. In the case of an iPhone, the making of voice calls is probably a small amount of all use cases for the device, it's more so a computing de

Not so sure I agree. In the case of an iPhone, the making of voice calls is probably a small amount of all use cases for the device, it's more so a computing device with a phone peripheral. But a washing machine's main function is to wash, and the computer controlling it is really secondary to its main function. The computer could be removed and it wohld still be essentially the same function with relays and timers. If you take the computer out of the iphone and replace it with relays and such to control the "phone" part of it, then it wouldn't resemble an iphone at all, and have virtually none of the functionality that an iphone has.