I have a childhood friend who literally refers to everything as a Ponzi scheme, much of it is out of humor. However, very much really is.

Anything that has the "greater fool" theory at work is essentially a Ponzi scheme. Take the stock market. You need someone to pay a higher price than you did to make money, greater fool.

I have been involved in markets for years and in the end I know it's a zero sum game. I make money when someone else is the greater fool. Sad, but reality.