I agree with you generally and consider stock-picking to be gambling.

But retail traders can use the markets to make bets on overall economic growth. Buying a stake in hundreds or thousands of public companies is a clear bet, and you actually do own something in a legal sense.

With crypto trading, it's unclear what your bet is -- other than the continuation of the Ponzi scheme. You don't own anything, and the coin has no value as soon as people stop believing in it.

If retail investors understood that nature of crypto, I'd be fine with them gambling on it. But most of them are tricked into believing there is underlying value in the coin when there actually isn't (see also: NFTs).

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.

But I am referring to investing into a DeFi project as a VC (= receiving tokens), not trading in Defi. Why is that not equivalent to investing in Robinhood as a startup?

With that clarification I agree that it would be a Ponzi scheme. If the project is mainly accepting money from new buyers and routing it to early participants who are selling, then it's a Ponzi.