You can stay on iOS 15. Nobody shoves iOS 16 down your throat. Apple even backports fixes for most dangerous vulnerabilities for quite some time.
What you can't do is downgrade once you've found that you're not happy with upgrade. That's the most bizarre Apple thing. Unless you can jailbreak. Not sure if it works nowadays, back in days I was very happy to downgrade to iOS 6 with jailbreak on my iPhone 4S.
What you can't do is downgrade once you've found that you're not happy with upgrade. That's the most bizarre Apple thing. Unless you can jailbreak. Not sure if it works nowadays, back in days I was very happy to downgrade to iOS 6 with jailbreak on my iPhone 4S.