OLEDs were built in 1987 I saw my first VR demonstration in the 90s (and it wasn't cutting edge then). I saw my first AR demonstration then as well as part of an undergraduate engineering fair. And so on. I just looked up maglev trains - in commercial use since 1984.
I don't disagree that there hasn't been refinements, improvements, or commercialization of technology, but there hasn't been a technological leap or invention that I can think of in the 21st century.