He could actually be true, once cryptos are widespread and cash is abolished, goverments will be able to monitor all transactions, how much you make, what you buy, where you work, where you travel, how much taxes you have to pay, no more privacy at all, everything will be in the hands of few bankers and oligarchs.
http://www.zerohedge.com/news/2017-10-21/crypto-currency-calm-stormThis is assuming that wallets and addresses aren't anonymous though. Honestly, if they weren't anonymous, you're much better off using banks and fiat. Your finances would be hidden from the general public that way, as opposed to non anonymous cryptocurrencies where everyone can see your entire financial history.