However, at WWDC 2021, Apple announced a change to the Find My feature that will come in iOS 15 that will allow it to work even when devices have been turned off or if they’ve been erased. Apparently how this works is that whenever you turn off an iOS 15 device, it isn’t truly turned off.
Instead, it enters a low-power state and will act as an AirTag, meaning that it will continue to broadcast its Bluetooth signal so that whenever another device comes in proximity with it, it will be able to pick up on the signal and transmit its location. For those who aren’t comfortable with their phones not being fully turned off, don’t worry because you can disable it.
Users who don’t wish to take advantage of this low-power state can change their settings and disable the low-power mode completely, but this also means that in the event your phone is stolen or lost and it is turned off, you might have a harder time trying to locate it.