Well, lets do apples & apples instead.
X number of people, one group starts drinking. The other ½ start using heroin.
Another group splits using crystal meth and the other huffs paint.
Now, each must reach intoxication every day for a year.
Which group will have more survivors?
In shear numbers alcohol will have the most numbers, it is legal, socially accepted and many more heavy drinkers will not become alcoholics by definition as per any five cites you care to produce on what constitutes intoxication which will be applied across all 4 drugs.
Or we can make heroin legal, socially acceptable and have as many people use it as are now drinking.
The drinking group will be now illegal, socially unacceptable and the same numbers as the first set up.
Little old ladies who have a glass of wine will now take a heroin hit. Not just problem drinkers. Heroin is just a benign as alcohol or say cocaine… Right?
Think alcohol would still be the worst?
As a recovering alcoholic of 24 years and having seen many more, the number of old people with 30-40 years of clean living after 20 years of hard hard drinking, lose it all living in the street for years drinking are so many in number compared to to active drug addicts with 20 years of hard use who then have 30-40 years of clean lives and doing fine, well, they are really hard to find. I know not why since drug use is not as bad long term as is alcohol. As that study claims.
Addiction in many cases are bad. Some addictions are not as much a problem. Working crossword puzzles seldom ruins marriages costs the person their job, home, etc… It is no less an addiction and you can abuse crossword puzzles if you really work at it.