Moderate drinking is not a problem.

From a health perspective, it certainly is.
No level of alcohol consumption is safe for our health.

And it does assist with socializing

Which is a cultural thing. If people grow up seeing how alcohol is a social catalysator, they don’t learn that it’s perfectly possible to socialize without alcohol.

which seems like it would be beneficial for most people on here.

Idk, if that comes from a well-meant place, but it sounds kinda condescending.

The idea that people here are afraid of/resistant to drinking, yet will use cannabis and other materials seems very strange.

There are not just two kinds of people. From my experience those, who use cannabis or other drugs, are inclined towards alcohol use as well.