Even if you do manage to "change the government" in your country to prevent all financial crime and enable all legitimate business people to trade without graft or fear of criminals, I don't see how you can possibly accomplish doing that in some other country where things have been on the same cycle of graft and corruption for 150 years. Do you think that before Bitcoin, criminals had no access to the international banking system? My family's gold tooth fillings in a swiss bank vault would like a word.
You believe you smash graft by smashing the means, but you don't stop it. It's the same with Americans who think that by banning firearms, they'll stop criminals from shooting people. Quite the opposite is the result. Ban guns, and you end up with an unfree society and the criminals have all the weapons. Ban cash and ban crypto, and you end up with an unfree society in which the ruling class are the criminals, and they have all the levers to control and steal the wealth of individuals.
Look, I'm not making this up. Check out the litany of polities that restricted the movement of money (or the ownership of firearms) in the 20th Century. They can be ranked on this axis alone as a reasonable proxy for their degree of totalitarianism. Let's say from the outright banning of money under Pol Pot up to the Cultural Revolution under Mao, Stalin simply deporting millions of people who had any money at all...
And guns are just a sideshow. Money is the individual's only defense against the State, and against the state of nature that exists in the vacuum where the State does not exist.