Are there regulation on the production of cannabis on sale ? concentration and limits in amount of impurities etc ?
Yes, it is regulated. However, growers get to choose which labs they send their samples to. With those incentives, you can guess what happens next.
Other than that, I agree with the GP: nothing has really changed; those who smoked continue to do so, often relying on the cheaper black market; those who didn't like it continue to not partake.
I vape once every few months and it is nice to have access to legal weed with transparent pricing.
Keep in mind, nobody would have ever arrested you for smoking cannabis for ages especially in the west coast Canada. Sure it was illegal, but everyone has a friend who has been smoking for years.