The only thing that will make me upgrade my iphone 6 is if it’s waterproof.
Otherwise I really can’t see any reason I would. I’ve had it nearly 2 years and I’ve barely had to think about it, it’s just been there, doing it’s job quietly without fuss.
Unlike the Android phones I used to be a huge fan of, too much bloatware, too many clashing processes and upgrades that don’t play well with older (less than 3 years old) phones.
Waterproofing though, that would be a huge weight off my mind. Especially as a bike commuter with the winter coming.