It is a generational thing, but IMO you've got the wrong root cause. Discussion of the dangers of drinking stems from people choosing not to drink, and people are choosing not to drink because they are attending the kinds of social gatherings that are lubricated by alcohol less.
As such, I'm hesitant to point to the decline in alcohol sales as a public health win. If people were drinking less simply because they were choosing to drink less, that's probably a public health win. If people are drinking less because their social lives have evaporated, that's probably really bad.
Your factors are real, but I think both elements are at play. I admit I could be biased as I see gen Z as more disciplined, locked in, from gyms to lifestyle.
Socialisation, or lack thereof, is a great problem for many people and newer generations raised "online", when you get for free at home endless social media distraction.
But even the 20 year olds I've met in bars were likely to stop drinking way sooner than us milenials, which still get plastered, at least on special occasions.
the article also explicitly called out that boomers aging out of the market is a driving factor.
its easy to forget just how freakishly large that cohort is and how they are all steeped in alcohol as the primary way to an altered state.
As they get too old to drink for various health reasons it makes sense that california wine especially would take the hit because boomers also have all the money so they are the ones buying fancy wine.
the younger gens not backfilling the demand contributes but it was never going to be at boomer levels anyway.
Get ready for a lot more stories like this as boomers stop doing all kinds of things... traveling, buying cars etc.
As such, I'm hesitant to point to the decline in alcohol sales as a public health win. If people were drinking less simply because they were choosing to drink less, that's probably a public health win. If people are drinking less because their social lives have evaporated, that's probably really bad.