Apple says it is time to update to iOS 15

While iPhone users aren't being forced to update to iOS 15, Apple's decision to end security updates for its older OS mean users may actually have little choice. — AFP

If you want security updates, you need to be using the latest version of iOS.

I’m guessing there are a great number of people — my mom included — who never give a thought to what version of iOS is running on their iPhones. They just use the phone and don’t ever worry about software updates.