You’re right that it’s not ethanol alone. In a similar (semantic, not physiological) manner to the MAOI hypothesis for cigarettes shared in a sibling comment, the compound responsible for most of the negative health effects (not necessarily intoxication although it is involved IIRC) is acetaldehyde, the primary metabolite of ethanol.
As to additives, I’m sure certain ones contribute their own negative effects, sodium benzoate and tartrazine for example, but in that regard it’s the same situation as the food industry.
Imagine how much adulteration goes on, especially with bargain basement liquors and beers. Surely, pure ethanol is not our lone enemy in this fight.