Well I’m in the UK but people have been smoking the same amounts for the past ~15 years when grass became popular. Before then it was much denser ‘soapbar’ hash. Grass is a lot harder to smuggle and takes up more volume so it’s not being driven by that.
Those responsible for 2/3 of consumption have had their tolerance pushed up by rising THC levels the past 15 years, but they’re still buying the same amounts every month. The inbalance between THC/CBD is also causing a lot more anxiety and psychiatric symptoms to emerge and pushing people away from it.
I believe there’s some efforts in legal states to move away from the high-THC strains causing these issues, so you’re right that the illegality is ultimately causing these terrible practices.
I was citing the original article where it’s stated. It says it’s increased to match the tolerance of the people who consume 2/3rds of the product not some nonsensical fantasy it’s being done to make it easier to ship.