The answer is obvious: because there are still enough chumps to be tricked. There will always be people willing to believe anything, and there will always be others ready to exploit that.
Plus, you’re conflating things. Cryptocurrencies as technology aren’t inherently scams, it just so happens their features make them an extremely well suited tool to run scams with (which can take various forms), so much so that’s by far their most common use case.
2) Perhaps "The Markets Can Remain Irrational Longer Than You Can Remain Solvent"
BTW. CrYpTo is all going to 0. Bitcoin is going up forever Laura.
And any network that doesn't base itself around the best digital store-of-value asset (bitcoin) won't be able to compete with one that does i.e. ETH is going to 0. And by the same token so are USD, GBP, EUR, YEN etc. unless they change to be backed by bitcoin.