Those figures are not implausible. They just require context. (It would also be nice to know what period he’s referring to and what period he’s comparing them to.)
Alcohol is a societal problem. People had recognized the havoc it caused for many decades. The Prohibition movement started in the 19th century and had huge success long before the 18th amendment was passed. Many states were already dry before the Volstead Act made selling liquor illegal.
But the states that went dry were primarily low-population, rural states. They also disproportionately had large concentrations of Protestants who were against drinking for religious reasons. The population of the country then far more than today was concentrated in the northeast and upper Midwest. These states were far more urban, had far more immigrants, and were far more heavily Catholic with no religious beliefs against alcohol and ethnic heritages that included heavy drinking. Those states fought Prohibition but were outnumbered.
Urban areas had huge numbers of neighborhood saloons. Breweries were local because beer didn’t travel well and each ethnic heritage had their own traditions of brewing. Naturally the raw numbers of closings would be very high.
So what happened afterward? There was still a demand, but supply was drastically lowered. Gangsters could and did run enormous amounts of liquor across the border from Canada and into ports all along the Atlantic coast. Of course the feds could and did catch them and destroy enormous amounts of booze.
The Feds never caught up and the resulting crime wave eventually sickened everyone so much that Prohibition was ended. But supply and demand are never repealed.
First, the economics of smuggling made it much more efficient to run high-priced liquor over low-priced beer. Beer was always in short supply during Prohibition but beer was the favored drink of the masses. Although some certainly turned to liquor, prices for illegal booze tended to be much higher than legal booze had been. At the niftiest New York speaks prices would still seem high today, a fortune in those days. Smaller supply and higher prices mean less consumption. Less consumption means less abuse. Less abuse means fewer alcohol-related crimes, violence, and illness.
All cities had speakeasies. Bathtub gin was prevalent. Home-brewed beer was still made. None of these could match up to the earlier reality of 1800 professional breweries and 180,000 saloons. There was simply less alcohol to be had during Prohibition. In that sense it was a success. The costs of that success were high. It’s always true that spectacular public catastrophes get far more attention than individual traumas, even if the individual traumas are far more numerous. As everyone points out many more people are killed in bathtub slips and falls every year than in shark deaths or airline crashes. The latter make the papers, though. Same with Prohibition. People couldn’t measure the auto accidents that didn’t occur or the wives and children who weren’t beaten or the cirrhosis that never manifested. They could see every shot taken by every gangster plastered on every front page. That will win every time.
Prohibition was an invisible success and a public failure. It had to end. Did it work? Depends on your definition of work. Obviously people are still arguing that one out 70 years later.