Now imagine you have millions or billions of dollars. You do not want to hand over 50% of your income to tax authorities, especially if a legal way exists not to. And if you make the current legal ways illegal, the money will just keep flowing to invented ways. There will never be a way to avoid this, unless you have a centralized AI super computer that cannot be manipulated by fallible humans watching everyone’s cash globally and enforcing strict rules. And that will never happen.
Most of the Panama Papers revelations were not illegal behavior. This article says most of this is perfectly legal. I’m not sure what the scandal here is other than humans don’t want to give half their money away to the government.