While the Note 7 turned out to be a fiasco, it wasn't because of it's feature set. The phone was quite successful and beloved by its users up until it was determined that it was too dangerous to leave in the customers' hands. The Segway lives on, at least in concept, with hoverboards and similar devices at dramatically lower price points.

Limited screen size will always be an issue for mobiles and finding a solution without mechanical challenges will be tough. I would love a practical, sturdy and pocketable device that gives me the screen real estate of a tablet, but I'm not sure it will ever happen. I think some iteration of a wearable (i.e. a less horrifyingly ugly version of Google Glass) will be the eventual solution ... at least until a direct neural interface becomes reality and we all join the hive-mind.