Worst case, nuke all data
The contents of your iPhone contains personal and private details about every aspect of your life. If the worst happens and someone steals it, it’s good to know that the thief won’t have endless opportunities to guess your passcode.
I have seen strategies of allowing location data and enabling guest accounts so someone can maybe locate their phone. Maybe. This feature is awesome, because it doesn’t require location tracking turned off.
Go to Settings -> Face ID & Passcode (Touch ID & Passcode on an older iPhone)
At the bottom of the screen, toggle the “Erase Data” switch to on.
Now all data on your iPhone is deleted if the wrong passcode is entered 10 times in a row.