You can't prevent banks and affiliated governments from forcing their own coins. Like could you not use US Dollars? Exactly, you couldn't. You have to use them because you're forced to by law. So if any government decide to implement "national" blockchain and trace EVERY transaction you can't do anything legally.

Btw, you mention private coins. Do you know that bitcoin and other cryptocurrency is actually easily traceable?
The only truly private (and fairly distributed) coins are Monero, Karbo and Aeon. You can't trace transactions on their blockchains unless you're allowed to by sender. There are no other options. Everything else is open and traceable.