Earlier quoted context omitted.
In practice I've been cycling phones about every two years. I just checked and all resources I've seen puts the typical lifespan around this. I don't know what the distribution looks like though. I bet the distribution curves change if you bucket the pricing points. 3 years is ok. After you buy it, they've made 100% of the money they're going to make in the transaction. They need money to come in to support such an e…
I'm still rocking an iPhone 8, and it's just fine for me— came out in Sept 2017. At this point I consider Apple's commitment to long term support to be a key element of my loyalty to them.
Alas, Apple also supports some highly anticompetitive business practices (App Store exclusivity/tax, EMS/iMessage) which I do not want to support.