>I guarantee a black market would emerge immediately

FTFY

But seriously, this experiment is already playing out in NYC[0]. Every marginal % you tax a product, you push some number of consumers into the black market. At some point, the black market reaches a critical mass where the thing you're taxing might as well be banned.

[0]https://www.google.com/search?client=firefox-b-1-d&q=new+yor...