Hm.
Darwin at work, indeed. I remember I could drink up to 2 liters in one day when I was younger, but instantly swallowing 1.5 liters definetly can kill you. Even if you'll survive - your stomach will be severely burned and your liver will be almost dead.
My avarage vodka consumption is 100g daily if I don't drink beer (didn't drink beer for maybe 3 last months). I have it at the dinner table, so I rarely get drunk. I weight 90kg, but for someone who is only 45kg the result will be much different.
The problem is that now alcohol is pretty cheap and you can get it 24/7, unlike Soviet times when it was sold from 11:00 to 19:00. I really hate seing kids drinking beer

Alcohol consumption raised many times in the last 10-12 years.
"Average alcohol consumption" is like an average temperature in the hospital. There are people who doze themselves with a halflitre every day, there are people who don't drink at all.
We have different definitions of what "alcoholism" is. It stunned me when I have heard that in the 80s there were 5 times more alcoholics in the US then in USSR, no matter that it's pretty obvious that we drink more.
Another important thing is phisiological condition and metabolism. Also, people in Central Asia don't drink much, but they
smoke and
chew. Guess where general health was better.