Also, the usefulness of alcohol may be all in its facilitating social interactions. I'd like some science budget spent on trying to prove that Europe surged to prominence on the back of it's alcohol consumption.
EB
Well, the fact that Europe was consuming more alcohol than most of the societies that it surged ahead of and continues to do so is evidence against any notion that regular alcohol consumption does notable harm to any of the factors important for societal progress.
And the increasingly heavy drinking in the parts of Asia that are also doing increasing well pretty last half century is further evidence against such aggregate harms of alcohol.
Also, there is scientific evidence in randomized experiments that modest levels of intoxication improves creative thinking and problem solving that requires insight (in contrast to solving problems by merely applying known formulaic solution procedures).
Creativity and insight are what are essential aspects of intellectual and scientific progress that requires not merely new applications of old ideas and assumptions, but whole new frameworks that don't make the same assumptions. Of course, science also requires lots of tedious work and attention to detail in the collection of data. So, while being drunk all the time would hamper scientific work, it is highly plausible that occasional intoxication by some of the people who are trying to construct and/or apply scientific theories in novel ways would have a net benefit to the intellectual progress at the societal level.
It is also worth noting that their is a positive correlation between alcohol use and general intelligence. Below is just one graph from one study, but others using different intelligence measure show the same result.
This relationship holds up even after controlling for just about every plausible confounding variable you can think of (sex, race, ethnicity, religion, marital status, number of children, education, earnings, depression, satisfaction with life, frequency of socialization, childhood social class, mother's education, and father's education). This suggest some kind of meaningful and more direct relation between drinking and intelligence, but the exact causality is still hard to tease out. There are reasons why more intelligent people might choose to drink, such as to use alcohol quiet their more chronically active mind (making alcohol use more a byproduct of greater intelligence). Regardless, the positive relationship is evidence that there are no damaging impacts of moderate alcohol use on general intellectual skills, that are strong enough to counter whatever produces the robust positive association between these variables.
That doesn't mean extreme drinking won't harm your brain or that being highly intoxicated doesn't impair you while drunk. Those are atypical instances that can have effects that have different effects than the far more common instances of people drinking modest amounts on