Rather than writing thousands of words about what society should do, my point is much simpler. To give an analogy: a private payment technology can be a powerfu

Rather than writing thousands of words about what society should do, my point is much simpler. To give an analogy: a private payment technology can be a powerful system like a general purpose web browser, or it can be like a more hobbled system that can only browse pre-configured web pages and image formats chosen by the developers. Both options are viable, however: the problem comes up when your use case (or your country’s use case) calls for a “browser” with a very specific set of restricted functionality that is greater than the functionality offered by the hobbled system that’s available. In this case you have a choice. You can ban all browsers entirely. You can use the hobbled browser that doesn’t meet your needs because that’s what’s available. You can try to add new functionality to the hobbled browser, which can be a hard path to follow. Or you can hope that instead of a hobbled browser, there is a more powerful full-featured browser that you can strip down to have the specific set of features you want. In the best case this is easy: just a matter of changing a configuration file. In the worst case maybe you have to snip away some code. To continue this silly analogy: it’s vastly easier to remove PDF support from Chromium than to write a brand new PDF renderer into software that chose not to have one. Obviously I’m going to have to ask you to take my word that in this case a powerful privacy-preserving payment system stands in for a full-featured browser, and it’s relatively easier to “strip (privacy) features away” from a strong privacy system then to make a weak system more private. I’ve spent a good chunk of my life thinking about this exact problem so I feel confident making this case. The remaining point you raise is essentially the following: the mere existence of privacy-preserving payment systems deprives societies of choice. This holds in the same way that the existence of, say, Chromium or Firefox makes it impossible for some country to plausibly mandate a browser that can only visit selected web sites or use file formats chosen by the government. The best thing I can say about this argument is: tough luck. Better (centralized) privacy-preserving payment technologies exist. You can’t make them go away, any more than you can hope that Chromium or Firefox will stop existing. If the success of your preferred system depends on the non-existence of other technology, and that technology is already out there, then you need a better plan.