Most market anarchists believe that black markets have a role to play, but not very many think that it's the primary way to bring down the state.
The most beautiful thing about agorism is that it doesn't
need to bring down the state in order to get results. You try, as much as you can, to live freely
in spite of the state. The more people practice agorism, the more varied and specialized the activity in the countereconomy is, the more completely it will be possible to opt out of the state. Agorism is practicable paralell to statism. "Alongside night", if you will.
Of course, without the state things would be a lot easier. It'll be very hard to get more advanced activities going in the countereconomy while the need for secrecy lasts. I'm mostly thinking of complex, specialized manufactured goods. I'd love to see agorist-made microprocessors, but I'm not holding my breath.