The challenges are gone. The height of civilization has been reached. Bored silly, we need SOMETHING to rail against, view as life-threatening, hate, oppose, worry about.
Interesting how some fiction captures the concept well:
Did you know that the first Matrix was designed to be a perfect human world? Where none suffered, where everyone would be happy. It was a disaster. No one would accept the program. Entire crops were lost. Some believed we lacked the programming language to describe your perfect world. But I believe that, as a species, human beings define their reality through suffering and misery. The perfect world was a dream that your primitive cerebrum kept trying to wake up from. Which is why the Matrix was redesigned to this: the peak of your civilization.and while I can't find the quote offhand, H2G2 notes that future medical science reaches the point where all injuries and diseases are eradicated, boring everyone to the point that artifically induced injuries are provided to motivate people again.
- Agent Smith, _The_Matrix_
The paradox of utopian dysfunction is a common theme in science fiction. Like so many lofty goals, paradise only draws us until we reach it. The thrill of the hunt ends with the capture.