I don't think most crypto is built to obfuscate. It's built to bypass centrally controlled monetary system. With the exception of some specialty crypto created to obfuscate, it's really not nearly as good at hiding transactions as say, cash.
Technically it might not obvuscate, but practically it does.
Critically (compared to cash) it allows remote transactions. Cash requires presence which limits the customer base geographically, and carries enormous personal risk. (you're already transacting with a criminal, do you want to be alone with him as well?)
The killer app for crypto is illegal activities. (which may in some cases be moral, but nevertheless are illegal.)
As a side note, the volatility in the crypto value, caused mostly my legal speculators being exploited by scammers, hurts the utility of crypto in all contexts, including illegal ones.
