There may be a massive confounding factor in the type of alcohol consumed.

The more permissive cultures tend to be beer- or wine-centric. I have never been deeply interested in addictology, but the few (older) works on alcoholism I have read mentioned that beer and wine drinkers tend to develop a different sort of relationship with alcohol than hard drink consuments, in the sense that they have a hard time abstaining entirely, but fewer of them develop into the full-blown "gin zombie" type.

I disagree. You see less depictions of beer or wine addicts despite them (at least from my experience) making up the majority of high-functioning alcoholics. I don't know for sure why they're depicted less, but my running theory is a combination of not being tragic enough for drama focused on alcoholism and being played for jokes with things like the "wine mom" stereotype. They also tend to be a lot better at hiding their alcoholism due to their type of drinking being more accepted. They have a different relationship with alcohol, but not necessarily a better one (arguably a more dangerous one due to the relative societal acceptance of their type of alcoholism).

"high-functioning alcoholics"

That's the crux of the situation, though; on hard liquor, the slippery road to becoming a non-functional alcoholic is much steeper.

There also might be a gender difference. In my experience, men who drink wine, mostly drink with friends and self-limit. The sort of men who are prone to alcoholism won't be satisfied by mere wine and will proceed to hard drinks quick. On the other hand, women often drink wine alone and might develop a daily habit that degrades into full-blown alcoholism even without resorting to hard drinks.

FYI, I barely drink at all and I dislike sloshed people (incl. myself when I rarely get intoxicated; it is an unpleasant state to be in). But even hell has layers.

I might also be biased. My dad was a "high-functioning alcoholic" who primarily drank beer. I also suppose that my definition of high-functioning might be a bit different as I think it's just as dangerous as non-functional alcoholism because it's easy to hide. My dad hid his problem well, it was only when he almost killed himself by driving off a cliff into a lake while he was shitfaced drunk that he decided to sober up. If he wasn't as good as hiding it he might've been pressured into stopping before he did as much damage to himself and those around him

In my midwest area it seems like you can tell who are the alcoholics right away because they buy and drink cheap beers 90% of the time. Maybe to make themselves feel less like an alcoholic because they aren't drinking hard liquor, and it seems someone is more likely to say something if they see someone down a half+ bottle of vodka themselves, but nobody ever says anything seeing someone down 10+ beers.

I suspect that's not so much a confounder as one of the mechanisms.

These things are not comparable. Alcohol is so old a thing we not only built plenty of stable cultural norms around it but we even developed genetic adaptations.

And speaking of culture, as an Eastern European I would argue our rules regarding alcohol are not soft. Yes, we drink, even expected to drink on some ritualized occasions. But contrary to Hollywood depictions, it's not cool to be a non-functional alco in our lands. When society decides you can't manage yourself, it builds harsh zone of exclusion around you. Imagine you have an uncle Jim who is constantly doomscrolling and for that he has no chances with a good reliable woman, his job opportunities are limited to something non-prestigious, people talk about him like he's a dimwit, even kids look down at him. He's recognized as a failure of a man and parents don't miss a chance to remind about the bad example to their kids. That would be "not-hard" rules EE style.