I think this supposed American dream was only ever a ruse, a Hollywood propaganda. If it ever existed it only applied to a certain demographic and was never actually a possibility for majority of Americans.

In the past decades (since the late 70s at least) Hollywood has slowed down it’s propaganda machine in favor of more independent film making (or the propaganda has shifted elsewhere; mainly the military during this century), so the illusion of the American dream is slowly but surely wearing off. In the meantime our jobs suck just as much as before, possibly even more, and are paying even less.