Why can't the iPhone 12 mini battery percentage be shown in iOS 16

With iOS 16, the battery percentage option is now available on iPhones with a notch except for iPhone 12 mini, ‌iPhone 13‌ mini, iPhone 11 (regular), and iPhone‌ XR. These models don’t have enough room to display the percentage.

To view Battery Percentage on any other phone with the Face ID "notch" at the top of the screen open the Control Center by dragging down from the battery icon, or add a battery widget to your Home screen. If you examine the status bar at the top of the screen you will observe that there is no room to put the battery percentage.

See→Use widgets on your iPhone and iPod Touch

Probably because it would be unreadable.

The percentage in iOS 16 is placed inside the battery icon. At the size it is on an iPhone 12 Mini, it would probably be close to impossible to read.