Re: Wouldn't it be nice ..
Frankly, it'd be nice if sensibly sized (<= 4") phones of decent spec were to become available again. If I want a device that required both hands to operate, I'll use a 9" tablet. For a phone, I want to be able to reach the top corner with my thumb easily, and being human my thumbs happen to not be 6" long.
As for becoming taller and narrower, this is again the consumer optinion being shaped to maximized profits - the less square the screen, the fewer pixels there are for any given diagonal size. Fewer pixels means higher yealds, which means lower cost and greater profit margins. We have seen this on desktop displays where things went from 16:10 to 16:9 and more recently the trend toward "ultrawide" screens.