There's also the fact that the black market is massive and deeply-embedded in American (and Canadian) society. Even without taxes it was never going to just disappear, certainly not in a single generation. Add to that the fact that most states still don't have legal weed, so wherever someone is growing they are not far from an illegal market. Plus, with use so widespread compared to every other drug, there exists a large enough youth market to keep a pretty big black market going indefinitely.
How long after the abolition of Abolition did the black market for alcohol disappear?
I imagine bars opened more or less immediately and the big producers restarted production as soon as they possibly could (some had been making alcohol for medical purposes). That prohibition lasted 13 years, versus 60-plus years for marijuana. The infrastructure for mass production and widespread distribution never disappeared.
It’s still here, just small. While you can make your own moonshine for personal use, reselling it is illegal. Find yourself some black market spirits!