How to reset iPhone simulator
For iOS 14 and newer:
Device > Erase All Contents and Settings...
For iOS 11 and newer:
Hardware > Erase All Contents and Settings...
For previous versions:
Simulator > Reset Content and Settings...
(In earlier versions of the simulator the top menu entry label was "iOS Simulator"
For iOS 11 and newer, you need to go the top system menu and select:
"Hardware" > "Erase All Contents and Settings..."