Tax heaven bank accounts hold 30 trillion dollars? But there are only 3 trillion dollars in existence.
You know that dollar isn't the only currency in the world?
So 30 trillion is not the sum of safe heaven usd accounts, but just an usd evaluation of deposits in all the currencies?
A bank account is not a container that "holds" currency. When you deposit a $100 bill at your local bank, they don't take that physical bill and put it "in" your account.
Most of the "dollars" in the world are in the form of US Treasury paper. Paper dollars are only a tiny fraction of the dollars in the world.