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.