I agree; cryptocurrencies are a scam. But in general they're not Ponzis, with some exceptions e.g. the situation the parent poster describes where VC investors get "early coins" which are sold to later buyers.
To be clear, you're saying that you believe that every last cryptocurrency is a scam with no exclusions? To me it seems absurd that none are non-scams, and makes me think you're just making baseless claims.
It's been 14 years and if the whole space disappeared overnight what would change? The news cycle would be less entertaining I guess. So much so China was able to nuke the whole space from orbit and what? Crickets.