Only because it's legal. Most people drink at least some. There's no such thing as moderate heroin or meth use. You also don't get fired from a job for having drank in the last week. Now if you show UP drunk...
I mean, for other drugs you could count accidents involving them, murders during robberies, etc. If they were legal and as easy to obtain, the numbers for them would go way up Even more if use was also socially acceptable.
All the illegal stuff get still consumed. In fact, some are mostly consumed because they are illegal. Dealers make their money because they manipulate, push and convince their stock to new consuments, especially to young/naive people who dont know the difference between gov-propaganda, dealer-propaganda and reality.
I know, thats why i said "except for the high addictive drugs"
Well, i dont know many jobs doing drug tests, my work history is limited to money collecting with multiple rarely inspected jobs at the same time and then managing our shelter.
There is your logic bug. Most drugs are pretty cheap, some even grow wild. What makes them expensive is not the production itself, its hiding the production, transport and spread them without getting detected, bribing people and on the large/organized scale the druglords must also pay their guards, weapons, luxury, etc. and since some cops really do their work they also need to cover and replace lost staff/money/drugs.
Lets take a common example, weed. 1g goes for 10€, one plant produces 20-30g per harvest, lets take the middle and one harvest of a single plant brings 250€ - street price. But when its legal to own the plants you dont pay the street price. And just like every legalized common product it goes into mass production and will etablish new prices, heavy taxed like tobacco, but still cheaper then the street prices, otherwise they would still support the druglords.
It would be the same for every single drug and without dealers pushing them to the people, without negative propaganda from govs and positive propaganda from dealers it would be up to science/docs/shrinks to spread the truth. In the end it should be up to the people if/what they consume and govs should only care about spreading the knowledge so people can make educated decisions for themselves. Everything else is just dictation and supports those who offer it despite the laws.