Since it was legalized here in Washington the police have mostly stopped paying attention to people selling it illegally and avoiding the taxes. They also don’t seem to have any interest with people now growing it in their homes for resale and for their own use. My guess is that the state is getting nothing from the vast majority of marijuana that is being consumed. I assume also that the increased supply has lowered the price considerably for those avoiding the taxes. However usage also appears to be up also. The smell of marijuana seems to be everywhere so maybe demand has kept the price up.
Historically there was bootleg liquor to avoid tax, but decent bootleg liquor is a lot harder to make than pot, and therefore easier to keep out of the market, so what you’ve observed makes a lot of sense to me.