How is the phenomenon of “keeping up with the joneses” a distinctly american concept?

The need to compete is not necessarily a unique American Trait. It exists everywhere in every land in almost every household.

The phrase means that the competition takes place with physical possessions. I have a 2018 Honda Civic. You have a Ford F150 truck. That makes you walk like a peacock because yours is better than mine if we two are the only ones competing. We are going by his rules that bigger vehicles are better. But mine has gone 200000 miles with no problems.  Doesn't matter. Your truck costs costs more. That's the rule those trying to keep up with the Joneses uses. That's the American Version. Or it used to be.

Other countries play it differently. There's what the children do. My son the doctor. My daughter the lawyer. 

But America based competition with the Joneses on money.

My favorite candy is gummy bear