Drinking is about experience. Usually people overdo it a few times when young and from that point on know how drunk on their way to too much they are.

Personally I have gotten drunk to the point of vomiting and needing to sleep it off. Never more than that, so I can’t report on blackout drunk.

But I’m personally of the impression that drunk people that get aggressive or do irresponsible shit usually want to do this anyways and alcohol is just a way to excuse for them acting that out. The reduced inhibition and the social stigma is a good combination to dare and have cover because you are a drunk.

As to why people want to act that out, I’m assuming they have unresolved issues that come out that way. And those issues are probably hard to control. So these people should probably not drink and get therapy instead.

Least, there is a factor of mild drinking that helps talk about things. So there is a factor of alcohol that can help with certain issues like social anxiety or daring to talk to somebody about a long held problem. So its a mixed bag.

Alcohol is not healthy, no amount is. But it helps to cope with reality, so with care and the right measure it can be a plus in life.