Remember, the reason we have no financial privacy these days is because we have book-entry settlement, which relies on biometric identity, known physical location, and the force of a nation state as the ultimate "error-handler" to prevent repudiation in the transaction protocol.
Yes, and cars break down because there are service shops. Utter nonsense. There is no financial privacy because because those who would like such thing have less power (hired guns) than those who would not like it. And those with controlling interests in modern societies do not like it because control would be lost, and population harvesting (aka taxing) would have to be radically changed, and that is expensive. The system is self-supporting. Idea that somehow smart algorithms will bring financial privacy is a good starting point for cryptoaddict's wet dream, but in reality has the same chance of success as survival rate of armed citizens against the government. Zero. (However, brandishing weapons and algorithms may alleviate some acute distress caused by excess testosterone levels :) Use of government-controlled, issued and supervised payment methods/instruments is in place because it is proscribed, not because "money/checks, etc. exist". Money is a highly artificial entity in the first place. It is "natural" to use currency-binded valuation as it is natural to go to church. And theorizing on money and economy in general has similarities to religious rituals. Therefore constructing computer-assisted anon payment schemes "because it is cheaper that way" is pointless. Money is not there to make your life easier. Money exists so that you can be taxed and conditioned to desired behaviour at minimal cost. Anonymous payments defy the principal reason money exists for, and is sanctioned (and enforced) by the state. The only way for society (or loosely coupled individuals) to function without abstractions like money (that need organized gun power to maintain) is direct exchange of goods and services with enforcement based on close relationships between parties. Has been tried, several thousand years ago, and such societies were annihilated by others who did organize. Which seems to be the fate of any anarchism in general. Barnmen