Cryptocurrency isnt hidden. Its quite the opposite. Exchanges are not decentralized, and you pay taxes on any exchanges you make. The only thing crypto offers over traditional currency is an indelible transaction register.
Blockchain will eventually be omnipresent. The only problem right now is comprehension and IT implementation capability.
No, it isn’t really hidden at all. In many ways it’s more transparent than regular currency transactions. Buying and selling crypto certainly isn’t hidden. Transferring crypto to another party ... Not hidden, but can the transaction be traced to personal identities? That’s a little more difficult than following bank deposits.