Every OS upgrade means older hardware will no longer be supported. Here are a list of devices that will get iOS 10.
List of iOS 10 Compatible iDevices - Less Wires
List of iOS 10 Compatible iPhone, iPad, and iPod Touch Models [Updated] - MacRumors
These iPhones and iPads may not get the iOS 17 update - gHacks Tech News
Here's every iPhone model that will get Apple's iOS 17
Know iOS 10 Compatibility Devices List: iOS 10 Supported
WWDC 2019: Here is the list of iOS 13 Device Support- The Mac Observer
IOS 11: A Giant Step For IPhone And List Of Devices Getting IOS Update And Features - Wirally
iOS 18 Supported Devices List REVEALED !
iPhones and iPads that will -- and won't -- work with iOS 10 - CNET
These iPhone models won't get Apple's iOS 17
iOS 18: Possible release date, new features, supported devices and more