I agree that mass production and the change in lifestyle it allowed for the middle class was the basis.
Commercialism was present in early America. The rich looked to England and France and imported almost every item in their houses using catalogs issued by manufacturers. Jefferson was perpetually in embarrassing levels of debt from his spending. The newspapers of the day also carried many advertisements for products and services as the cities grew larger.
The trend just went upward over the 19th century. The more industrialization the more products there were to buy. Factories drew people off farms and into the ever-growing cities. Buildings were plastered with advertising on every surface. Cheap newspapers begin before the Civil War when the rotary press was invented, and these spread the availability of goods to the masses.
It really took off after the Civil War. That spurred industry, which was fed by the millions of cheap labor immigrants landing in the country. All the world-changing inventions were bunched into a quarter-century from the telephone to the electric system to the automobile and airplane. Distance was conquered, the world became smaller, everybody wanted a piece of the new.
I think the Puritan work ethic is vastly overstated. More people gave it lip service than lived up to it. The loud voices were those like today who decry our consumer culture while denying themselves nothing.
Everybody makes a big deal of the 1920s because all these forces culminated at once. For the first time more Americans lived in cities than in rural areas; the war broadened the cultural horizons of millions; suffrage gave woman the vote and individual identities; prohibition created the first widespread underground culture; wealth was prevalent everywhere except on farms, which helped empty them out ever more. And it’s easy for authors to contrast the 20s against the Depression and war years. But if you spliced them together, the 20s and the 60s look incredibly similar and it becomes obvious that one single trend is involved, temporarily interrupted by weird one-time events.