I'm sure that's a huge part of it. I also wonder if GLP1 meds are having an impact.
This is no doubt part of the reason why the farm bill loophole is being closed: lobbying pressure from those whose bottom line has been impacted.
Also, help for alcohol abuse is more accessible and socially accepted than ever before. Sober movements overall are having a moment in the US, even though some traditional recovery membership like AA is slightly declining.
This is pretty much the explanation---the decline in alcohol revenue mirrors the rise in cannabis sales. The alcohol decline started in 2012, when the first states legalized marijuana.