Apple discontinued support for 32-bit apps in iOS 11. There are a large number of apps that never got updated to 64-bit. Because Apple controls which iOS versio

Apple discontinued support for 32-bit apps in iOS 11. There are a large number of apps that never got updated to 64-bit. Because Apple controls which iOS versions can be installed on a given phone at a given time, it's impossible to upgrade a phone from the OS version it shipped with to any other version besides the latest.