Given the importance of the "gnôle" (a french word for a often home or clandestinaly made strong spirit in France) in rural parts of France to this day [1][2], I am pretty sure the author is underestimating the importance of spirits in history.
[1] usually mixed with coffee several times during the day, and very often a shot glass in the evening
[2] I've never seen a sober postman when I visited my grand parents as a kid in the 80's and 90's. Back in the days they weren't timed and would be invited for a coffee at every single farm they visited to talk about the news of the day. He really served as a local and vocal newspaper for all of them. The coffee itself wasn't strong in cafeine, but was almost always served with "la goutte", a small but significant amount of spirit.
I remember reading a letter from an Austrian Trappist abbot, from Bosnia in 19th cetury, to his friend in Austria. The letter was mostly complaining about locals excessively drinking plum brandy. He had cut down all the plum trees on church land. Forbade coming drunk to mass, but then people would just get drunk after mass. Founded the first brewery in Bosnia to get the people to switch to beer. Even set up a fruit dryer so that the church would dry the plums for free so that the people did not have to make brandy out of it come winter. In January, a "jolly company" from the village came to visit him thanking him for the the dry plums. Usually by this time they would run out of brandy, now they had dry plums and were making it from them.
It was a letter by Franz Pfanner from 1873. Sadly, after a short search, I could only find a version of it in Croatian[1]. Google translate seams to do an ok job on it.
It also depends of the region you live in. In Brittany for example people drunk a lot of watery wine and sweet cider but they drunk it in quantity for some of them.
You canread in Jean-Marie Deguinet's "Mémoires d'un paysan bas breton" (19th centuary) that people were drinking a lot of cider and particulary his wife who was a cider Alcoholic.
The gnole as you speak is more something that became popular amongst the Poilu during the first world war and after, I'm not sure if there was loads of people drinking it in the past but it feels like the spirits became more popular by the end of the 20th centuary.
My grandfather had a cider brewery and even the apple juice he made had a bit of alcohol from fruit fermentation. Something below 1% though so we drank it as kids.
I would say in the case of cider you have to drink an awful lot to feel intoxicated, you definitely suffer from diarrea before you feel the alcohol.
Isn't [2] what happens in Bienvenue chez les Ch'tis? Postman is drunk every day at work, and his new boss thinks he's got a drinking problem. Turns out he gets served, or even forced to drink a nice glass of liquor at every stop.
[1] usually mixed with coffee several times during the day, and very often a shot glass in the evening
[2] I've never seen a sober postman when I visited my grand parents as a kid in the 80's and 90's. Back in the days they weren't timed and would be invited for a coffee at every single farm they visited to talk about the news of the day. He really served as a local and vocal newspaper for all of them. The coffee itself wasn't strong in cafeine, but was almost always served with "la goutte", a small but significant amount of spirit.