More than that, they’ve gone up to 6 years before with the iPhone 6s. It didn’t get iOS 16 this year, but it got iOS 15 last year and will continue to get security updates for as long as Apple wants to keep supporting it.

My iPad mini 2 (2013) stopped getting major iOS updates with iOS 12 (released 2018) and got regular security updates for years, and I even got a security update in August this year. Granted it was to fix a big vulnerability, but it’s almost 10 years old.