Unfortunately of the two possible ends to this cycle a permanent tyranny appears the more likely one.
We are a perhaps only a single generation away from the time when technological advances will probably make overthrowing a tyranny nearly impossible once it is established.
I've also been getting increasingly worried about that possibility. What worries me most is a 1984-style scenario where the game is constructed such that even the people "in charge" can't escape. If
someone is in charge, then there's some hope, since I think that almost everyone is at least a little decent, and even most tyrants would not want to completely crush all freedom and virtue. But with technology, I could see humanity trapping itself utterly in some perpetual machine with no freedom or progress of any kind.