I think another big consideration is ecosystem costs.
Particularly with Apple, people probably think about more than just the phone when considering their upgrade cycles.
My upgrade cycle has been
2009 iphone 3GS
2011 iphone 4S
2014 iphone 6
2017 iphone 8
2023 iphone 14
but while the time between phone upgrades has slowed, in the later years I've also bought an Apple Watch and a couple of pairs of AirPods during that period.
Even now my current pair of AirPods have pretty shitty battery life, but I'm holding out on buying a new pair for as long as possible because I've just given Apple a bunch of money for a phone and I feel like I should try and have some sort of vaguely sane limit on how much I throw their way.