It's all preference and trade off
you either pick
- big screen
- better battery
- image stabilization
- landscape home screen
- 1080 P
or
- easier handling.
for me I had to have the bigger screen. Things like browsing, netflix, reading, youtube, etc are not very enjoyable and almost unbearable to me on a smaller screen, I'd much rather just wait to get to my PC. The bigger screen actually makes it worthwhile to do these things which makes me fully utilize the smartphone regularly to its' full potential rather than just for calls and texts.
Plenty of people utilize the smaller iPhone to its fullest potential for the things they want to do. Both have the same features just in a smaller size. The battery in the smaller iPhone is enough or they carry a battery pack or charger in the car. They do not just talk and text and it is so much easier to carry and handle.