As long as you can sell it for USD it's not worthless - you don't other goods/services - although that said the list of those is still growing.
The fact that I can send money (liquid fiat) to a friend without going through paypall/zello/etc. is valuable.
The only thing that could make it a "scam" is the promise of money, which I 100% agree that using crypto to "make money" is stupid and is a massive problem.