I'm curious what happens to the people who were surviving on the cash from selling it illegally. Some of them are poor slobs. Some of them are organized crime. Are they just going to try to sell it at a lower price since the police cannot tell where you got it from and might not even care anymore? Tax savings alone radically reduces the price.
They can now get a legal job selling it over the counter. They can get licensed and sell it legally via delivery or whatever (I don't know the regulations). They can leverage their growing operation into a legal business that sells to dispensaries. They can get a job in another field...though, the skills acquired through dealing illegal drugs aren't necessarily very marketable.
I dunno...but, we didn't, as a nation, mourn the end of bootlegging as a career option when alcohol prohibition ended. So, I'm not going to mourn the end of the small-time drug dealer (or the large scale cartel dealers, either).