Probably worth highlighting that I could not find a single direct reference to Neel Kashkar (the person who apparently said that, actually saying that it's a Ponzi scheme.

He used "dumpster fire" in past, which is quite different.

He knows that it's not a Ponzi scheme, because there is no fraud. It's like the dollae, stocks, interest, money printing and some VC investments, etc. which aren't usually Ponzi scheme either because it's not illegal.