I carry my phone because I’m listening to podcasts while doing my household chores, and my home has 3 floors. I must have the phone on the same floor to have a good connection with my headphones. If I lived in the apartment I would simply put it somewhere in the middle where Bluetooth reaches all the rooms.
Apple devices are (much) more challenging, but there are ways there too… typically, those stolen/locked devices are stripped for parts (or used in a scam where they phish credentials from the original owner).
That said, it’s not impossible. I’m not fully clued in on the details, but from what I can tell (having seen shops in Africa, India and China selling these), they appear to be jailbroken, have connectivity disabled or heavily limited, and still be “useable”.
A little like when they started blacklisting the IMEI of mobile phones, places started cropping up who would (illegally) change your IMEI.
But all this is for when a device is marked as stolen/blocked… for a child, they still have access to the device; and bypassing the apple controls then is a little easier 