Alcohol lowers inhibitions and alters decision making. Drinking a lot of alcohol more so than casual drinking. Frequently drinking a lot of alcohol has a very high area under the curve of poor decision making.
Functional alcoholism can come with delusions of sobriety where the person believes they’re not too drunk despite being heavily impaired.
So they’ll do things like have a few (or ten) drinks before checking their email. It makes them a better target for everything like fishing attacks, as one example.
It’s not just about enemies holding it against you.
Phishing is not the problem here. Your laptop isn’t getting SIPR emails with links to fake login screens.
Still not as bad as being susceptible to blackmail or bribes