One of the factors that led to some technologies being "underdeveloped" is the improvement of other technologies. For example improved telecommunications and miniaturization have reduced the need for better transportation.
I know everyone thinks I am a boring cow and a curmudgeon.
But one of the reasons for the future of the futurists not arriving is that the future (at least technological one) is created by engineers and researchers not science fiction writers. Which is how it should be look what you get when take science fiction writers too seriously you get Scientology, Objectivism and al-Qaida
pneumatic sliding doors and flip-phones are awesome.
Years ago I worked at a company that installed a large APC backup power supply, which was almost as big as a kitchen fridge and had some futuristic styling to it. Although it was no more than a big battery, it looked like what a 1980's sci-fi movie megacomputer prop would look. So I said, "they should provide a module you can install on these that makes it go 'Wub-Wub-Wub-Wub-Wub-Wub!'"