There are more types of phones than just iPhones, and there have been enough high profile incidences of zero day exploits that allow you to exfiltrate data from

There are more types of phones than just iPhones, and there have been enough high profile incidences of zero day exploits that allow you to exfiltrate data from a locked phone to give a reasonably security conscious person pause to just hand over their phone to a stranger. Even if you think of the people you're giving the phone to are trust worthy there's just no good goddamn reason to risk it.