You miss my point. I personally will not be buying another iPhone if they do not increase the screen size. Apple will obviously continue to have success. I have a work computer (Macbook Pro) and I have an iPhone. I cannot justify buying an iPad when I feel I should be able to do everything I could do on it on my phone. I want a phone big enough to sit and play games and browse the web and watch videos without having to lug around my work computer or spend even more money on an iPad. Squinting at a 4" screen or constantly having to use two fingers to zoom in and out on every article is annoying as hell.(so much for one handed use) I literally do not use my iPhone unless I absolutely have to, because it's such an annoyance. This is my own personal experience, but I don't think it's unique. I prefer Apple's UI but I want the big screen more than I want a pretty presentation.
I am exactly the same and I suspect there are millions more just like us. I know a lot of people with iPhones and not once when this topic was discussed have I ever heard anyone say they were happy with the small display. In fact only on AI do these people seem to exist. On other Mac websites there is overwhelming support for larger displays.