Why does my iPhone only have iOS 12?

Hello ~ Are you sure? It should have been delivered with iOS 16 already on the device.Take a look here by clicking on and reviewing the links below…

Find the software version on your iPhone, iPad, or iPod - Apple Support

Identify your iPhone model - Apple Support

Update your iPhone or iPad - Apple Support

If your iPhone or iPad won't update - Apple Support

~Katana-San~

This is a user forum, you are not addressing apple here just fellow users

iphone 6 have a hardware which does not support higher than

Current: iOS 12.5.7, released January 23, 2023[10]

iPhone 6 - Wikipedia

you can try contacting apple Support ->  Get Support (apple.com) / Contact - Official Apple

Support

and or give them feedback -> Product Feedback - Apple

Hey maluleke146

If you have an iPhone 14 Pro Max, then your iPhone is delivered with iOS 16.

iOS 12 has never been available for the iPhone 14 series.

You can see your current software version here:

Settings > General > About