Unless you prove it is, it's not. It's not encoded in the UN's human rights charter, nor in pretty much any legal system out there.
Governments should protect you from other individuals accessing your financials except the government itself, but that's it.
> Cryptography allows individuals to use the force of mathematical law, superior to all other law, to enforce their privacy rights.
I am absolutely against the use of "cryptography" (which by the way any transaction system uses) and cryptocurrencies as there is one and only one purpose for such a thing: tax evasion and money laundering. There's literally no other purpose except far fetched arguments.
I think the concept is at least useful if you want to protect a right. Without it, in practice, it would be much more difficult to defend against the controlling capacity of raw force.
This is a baseless, so I think you're making a bad assumption. Finance is opaque at a low level because of arbitrage and physical trade, but it's the belief that the physical world dictates social rights (which are moral at the core, so let me know if you want to jump to morality?) is simply incorrect.
What's more, I think that the default position that finance should be private actively hurts society in innumerable ways. Unfortunately, without it, capitalism immediately breaks down into monopolies. So we live in the happy middle, as with many things, suffering the inevitable (corruption, blackmail, etc).
(Tornado cash, like most mixers, leaves too many loopholes in its contract to be proof against a concerted attack in typical practical applications - they usually leak too much partial information.)