I've always been Android, but the easy counter is just "why do people feel the need to replace their working phone every year."
Car companies have a new model every year and even among those who could afford to, very few people feel the need to have an annual car upgrade cycle. Products aren't (/shouldn't be) fashion.
Apple's got a weird cult thing going, partly because the first few generations were legitimately large upgrades. I'd be curious about the stats of how many non-influencers actually upgrade annually.