Look what thousands of years of Cannabis use did for the Hindus and Arabs, while Western Civilization was refusing to use it as an intoxicant, and was very much involved with alcohol (and advancing).
Good observation. They say correlation is not causation, and maybe they're right. But I believe you can find a lot of evidence with correlation. For instance Paul McCartney's (a huge dope champion) production after the sixties was mostly garbage. He wasn't the only big name, dope-smoking rock and roller who did all their best work early, and then produced crap later. Is there a correlation between heavy dope use and dulling of the creative senses? Maybe.
I wonder what Western Civilization would be like if it had steered clear of alcohol.