My father is still using an iPhone 4, 6 years after its launch and is now thinking of upgrading to a 7 in the fall and I have had a 5S for 2 years now and think I can pull another 2 years before I upgrade. These phones have longer lives then they use to but Apple sales I believe will remain steady since some old iPhone user has to upgrade and they most likely will pick an iPhone. There isn't much reason to switch to Android at this point.
The only thing that could take them off there perch is another revolutionary device showing up on the scene, but I think that won't happen for another decade.
The only thing that could take them off there perch is another revolutionary device showing up on the scene, but I think that won't happen for another decade.