[tluyben2]

Yes, but how? I agree and have spent a lot of (essentially useless) time on thinking about that, but this is complex unless you are a despot.

If we have no privacy left, you monitor all that you do on any foreign or local card/transfer etc (you ban crypto and put insanely high fines/prison on using it) and if that seems not to match what you reported as income/capgains/etc, you get an audit. What is the point of being rich and evading taxes if you cannot spend it? And if you move it to foundations etc, at least you cannot get to it, nor can you family if they live in this (fictional?) country as they would have to explain the same things.

In a society (probably a democracy?) where people value privacy and non-draconian laws, I cannot figure out how to make this work. Besides having educated and patriot people who actually would choose to pay taxes for the greater good. But these people do not start on their own (Bill Gates example of not minding to pay more tax) and they usually believe they can do better things with their money (for humanity). And that is usually not the case or way too biased; their right if taxing is paid fairly, but if evading, a problem.