I've reluctantly upgraded iOS here and there, mostly because my bank app requires it. Other than that, I've hated upgrading because there's always new UIs that are more confusing than before. Yes, there's sometimes some nice newer features (the call handoff thing is kinda nice at times), but... I'm also on an SE (just bought a new one in Feb) and much of the new stuff assumes newer/bigger phones too. I'd like security updates on previous iOS versions for earlier devices, but I'm also aware of the logistical problems that would create.