alt Hacker NewsAlcoholics (the really bad ones that we're presumably talking about here) don't consume because of social pressure. It's addiction and all the associated psychological and sociological complexity that implies.
I expect any comparison of alcoholism rates will need to account for social (particularly religion) and socioeconomic factors. An awful lot of addicts are engaging in escapism.
Addiction doesn't start until you've first started consuming a substance. The means by which you first start consuming alcohol vs. opioids are completely different, and the former is virtually always the result of social environment.