There's absolutely no way you could trust with absolute certainty that a private blockchain run by the US government You're right, you couldn't trust it with a

There's absolutely no way you could trust with absolute certainty that a private blockchain run by the US government You're right, you couldn't trust it with absolute certainty. they don't benefit from not being able to access the data they're storing in your scenario The government makes transactions it wishes was private all the time. A politician that could route money through a black box could perform many many patterns. Ollie North supplied guns to the 'good guys'/politically favourable team in the Iran-Contra affair with money from outside the sanctions. It's not required for the government to increase the privacy of money flow, but they could see benefit in it, for better or worse. You're right it is simpler to accept cash in a lot of ways. In a world of mass surveillance, showing up to meet your local drug dealer in a parking lot at 2am, is no longer private and nor is cash. Your number plate was recorded the whole way, your face hit facial recognition cameras and IR scanners at toll gates and the phone booth/mcdonalds wifi picked up your phone's IMEI as you drove past, which is linked to your passport photo you submitted to buy your phone, the cash you got from a bank or business has captured your face. A satellite captured your car moving every 5minutes(?) or so. The cash might not be 'on the books' but nearly everything else you did was, which you need to defeat with perfect opsec to be free from a government audit that can ping the FBI/CIA/NSA/private organizations officially or unofficially, legally or not for information about you. Absolutely Certain™ privacy isn't possible with cash either.