Too Long; Didn't Read
The evolution of digital currency came about in part to address the issue of online payments. Bitcoin is the best solution the world has to a currency with sound monetary policy. The transparency of Bitcoin, however, is detrimental and even dangerous at many levels. The public ledger of Bitcoin makes it at best pseudonymous. Physical cash beats Bitcoin in its privacy. No third party can track your spending when you use cash. The US dollar bill is still the most liquid and anonymous form of currency in the world today.