The American Dream was a neurotic delusion of consumerism created in the early 1920s for a small group and again in the 50s for a larger group.
But it was only a treadmill for people to run on. Consumerism is fundamentally STUPID. The laws of physics DO NOT CHANGE STYLE. Bill Gates can buy a new car every week but the physics won't change. Truly excellent products don't need to be redesigned very much. The fact that so many of them are changed so much is proof that they are absurdly designed. People buy too much for psychological reasons.
You can't run a planet of 7,000,000,000 people on bad algebra. There were fewer than 3,000,000,000 in the 1950s so the delusion was easier to sustain.