Ethanol gives you the good feelings associated with drinking (and the incapacitation) and it gets metabolized into acetaldehyde, which gives you the symptoms of hangover (flushed face, headache, vomiting, etc.). Asian populations have a much higher prevalence of variants of two genes that encode for proteins that turn ethanol into acetaldehyde and acetaldehyde into harmless subcomponents. The variants are much better at metabolizing ethanol (20x faster) and completely inactive at metabolizing acetaldehyde.
Almost all Japanese (>95%) have at least one copy of a "metabolize ethanol faster" gene, and somewhere around half have inactive aldehyde metabolism, so given the same amount of alcohol, they would be far less incapacitated than a European (and red, and puking). The net result is a society that looks like it has a massive alcoholism problem to the west, that isn't quite as bad as it looks.
The whole "dude weed is better it'll get rid of crime and so on" isn't something anyone takes seriously. Some people have horrible reactions to it (myself included) and it makes us anything but peaceful. And nowhere where weed has been legalized have alcohol sales died. People just use both. And if you want to dig through my post history, you'll see that I definitely don't have a "backward" understanding of drugs--I've got more than plenty of first-hand experience, and I've also moved from a "dude weed is good lmao" society to a zero drug society and I'll take the latter any day.
Crime rates in America haven't changed since weed got legalized. It's been on a fairly steady decline, albeit rising in 2015 and 2016 after some states legalized it. And while likely unrelated, murder rates have also significantly risen in Uruguay after marijuana was legalized.
And trust me, when it comes to crime, Japan doesn't need to model themselves after other countries. Japan's murder rate is the lowest of any country with over a million people. Maybe you should learn from Japan and start copying their laws? :)
You clearly have a backward and outdated understanding on crime.
If Japan and Korea were to smoke marijuana instead of drinking alchohol, their societies would be better off immediately.
You clearly have some very backward and outdated understanding of drugs, their effects, levels of harm, and recent scientific studies on drugs.