Apple

You don't need an $800 phone to be rescued - there are cheaper devices with the same capability (in fact, they often have larger antennas and are much more reliable in low signal situations).

The thing is though - most people don't even know Personal Locator Beacons are a thing, let alone own one, let alone have one on their person when they need it. People do, however, take their phone everywhere.

Hopefully soon this feature will be free and mandatory on all phones, just like the ability to call 911 even if it means roaming on another network for the call.