Also anecdotal, but I've owned ~every iPhone since the launch-day original iPhone. I still own every single one, and they all still work like the day I bought them. My iPhone 5 was replaced the day after I bought it due to a few dead pixels. My iPhone X came down with some kind of touch digitizer problem in the first few months I owned it, and again, Apple replaced it under warranty. But overall, longevity for my iPhones has been comparable to every other Apple device I own (e.g. still have the Mac II I grew up with; still works fine).