It seems to me that many members of the forum have outdated concepts about the Ponzi scheme. In order to conduct a dialogue in the right direction, we must first give a clear concept of what the Ponzi scheme is. And where, besides financial pyramids (as this market was dubbed), is it still used at the state level?
Only after that, it will be possible to scatter the terminology of Ponzi and brand everything in a row.
US Dollar - Ponzi Scheme?
It seems to me that you are using a standard deflection/denial strawman argument ("outdated"..."What about central banks?"... "Everything is a pyramid") that Ponzi/pyramid scammers have been using for years.
The only marginally gray area where schemes, which have no (or insufficient) core profit generation activity and hence pay out later investors' funds to earlier investors, should be labelled as "scams" is whether they lie about it or not.
This aspect has been discussed several times.
If you say "We are experienced FX/arbitrage/whatever traders and pay daily trading returns of x%", whereas in reality the x% comes from new investors money, then you are a Ponzi scam.
If you say "our scheme is based on a smart contract which allocates x% returns when new deposits are sufficient to do so" then it can be argued that it is a Ponzi "game", as there has been no attempt to mislead regarding the source of the x%.