For starters, because it's "might makes right" and double blatant standards all the way down.
Nothing particularly unique, for almost any empire in history has operated worked that way. Just as almost any empire eventually had to resort to increasingly more covert, corrupt and criminal enterprises to support itself. At some point, it inevitably will all come crashing down.
In the case of America, several generation will ask themselves how they could have been so dumb to let it get that far. No entirely fair, because their parents didn't really have the power to influence (let alone stop) any of it. Not without completely destroying the same system that also supported their way of life. Many people in the Soviet Union at some point knew at some point that the system was doomed, but nobody know how to change that reality for the better.
A lot can be learned from reading books written by Russians, about the collapse of the Soviet Union. Or books by Germans, after the end of World War II.
In fairness, it's hard to blame current day Americans for not clearly seeing what's going on, considering the level of cultural, institutionalized and commercial brainwashing (including deliberate division and diversion) that has been part of every aspect of life there, for decades (if not a century).
Still, there will come a day that Americans will have a rude awakening about reality and how those who run their country (be that government or private interests) have ruined their future and well being for a long time to come, just as the Russians and Germans once had.