As far as sf stuff goes, the 21st century has been disappointing. The moon landing was the farthest we got.
On the other hand, my personal life is much better than I thought it would be. There are cures for the diseases that killed my father, and I've already lived longer than my parents. There are cures for many forms of depression. In the preiod from 1950 to 1980, freedom expanded beyond what I would have believed possible -- freedom for Blacks, for women, even for gays; freedom of the press, freedom to travel, freedom of communication. In the same period, the average US income tripled, as did the GDP. Most important, we managed to control population and avoid World War III.
It is true that in 1980 Ronald Reagan put a stop to expanding US prosperity, and we've had a major recession every ten years thanks to Reaganomics. But Clinton put things back on track for eight years, and I have high hope that Obama will do it again.