Your first two sentences are in contradiction and the article has it right. The reason privacy is a threat to power is because the more of it people have the harder it is to raise taxes. Taxes are the crux of the entire system. What use is power without being able to raise taxes? It doesn't get discussed much because if pressured most people would rather abandon privacy than give up taxing others. If we all pretend that privacy and taxes can both be achieved at once we can at least get everyone to, in principle, agree privacy is an admirable goal and maximise what privacy we do all get.

Although with things like Monero and other privacy coins we have suddenly got an asset that is actually private and therefore fundamentally resistant to taxation. It is a weird development with hard-to-foresee implications.