they will move underground and continue to be used in the black and grey markets around the world.

The positivity of this can not undermined, the black market will always exist and it will forever be home to some people who take privacy more personal, imagine a privacy coin, isnt the DAO supposed to fall in the category of privacy coin?

you don't wanna live in a world in which the governments can see every purchase you make, it would be a totalitarian nightmare

Hence a use case for the privacy coin