Yes, that too, but also just fucking privacy. A basic notion that your financial movements shouldn't be an open book to any bureaucrat, functionary, corporate drone or algorithm under the sun. We rightfully take personal privacy seriously in many other things, but suddenly you try to apply the logic to something as deeply sensitive as one's economic life and many would-be nannies lose their shit. Many of you on this very comment thread sound like government agents ranting about "protecting children" with their attempts at encryption backdoors.
The only difference is that you apply it to preventing people from controlling the keys to how and where they keep or send their money. Why? Because "terrorists!" "Money Laundering!", Tax evasion!" Oh my! How many of these justifications wouldn't even exist if government wasn't so heavy handed in slathering on endless regulations to criminalize whole areas of human activity that never needed to be harmful or criminal in the first place?
I'll also note here that in many countries, employees at major banks and at major government offices collude with organized crime to a pervasive degree, and actively look at the accounts of people with signs of having come into large amounts of money (but without corresponding protective power of their own) for the sake of extorting or even kidnapping them. I live in one such country. It's easy to bleat about the need for KYC and making sure everyone "pays their fair share" (a thing that anyhow barely functions as claimed even in the most KYC-obsessed countries, since the wealthy use all kinds of legal loopholes and special connections to keep their funds safe) if you live in a place where the powers that be aren't overtly parasitical and criminal. It's a little more difficult to apply the same in other parts of the world.
