Not to mention the lack of modernized fractional distillation to remove the methanol. ALL Liquor had substantially more methanol back then. Notably, ones processed in leaded containers were particularly bad because volatile methyl compounds formed lead methyl compounds.
Lead methyl compounds can easily get into the body and brain, but then drop their lead when metabolized and the body can't get the lead to leave.
That's why it's interesting when you think about what "pure ingredients" meant to them. Like the French artistic and Society elite, who were like "keep only the purest recipes in rotation, to be available for sale at specific cafes." Like...y'all LOL.