Well, mail has to go through customs and cash is very easy to size. You can memorize the key to a crypto wallet and no one will know that you have it. If you tr

Well, mail has to go through customs and cash is very easy to size. You can memorize the key to a crypto wallet and no one will know that you have it. If you try to mail USD as remittances to a lot of countries, it simply will not arrive. It's also not always possible to convert between currencies legally. A number of authoritarian governments prevent their citizens from doing so.