The only reason why I could see someone doing this is if they wanted a phone to be a bit more mobile, easier to put in the pocket throughout the day, use with one hand, maybe better battery life. That said, I use my iPhone 6s+ as a book, planner, note taker (with bluetooth keyboard), and communication device. As much as I would like to go back to the smaller phones (loved the feel of the 4s), the way I use my phone, I don't think I could.