You should be living in some other universe. Most of the corruption stems from the fact that cash transaction history can be spoofed easily. There is no way to link cash with your identity linked to the tax systems. With digital payment, all the payments to/from will be linked to a taxable entity.

True enough, but this wasn't in the context of taxes - it was about avoiding getting ripped of by paying cash then having an entity claim you never paid them. Receipts are still good for this - signed receipts even better.