it's how they cope with their miserable life.

a lot of people are not full blown alcoholics, but alcohol dependents, as if they don't get shit faced, but they need a drink to function in ordinary situations.

I have known people like this. They can't interact without people without alcohol. So at work, at a party, or just getting a coffee... they have to drink. And most stealth way to do this is a nip they can drop in their coffee or whatever. Typically they are not drunk or visible intoxicated, but without drinking they feel anxious and miserable.

it's called Alcohol Use Disorder, or if you go by the alcoholic stages, it's stage 1-2 on that scale.