Earlier quoted context omitted.
They weren't always. In fact it took many centuries for this to happen. The history of cocaine in the US is quite interesting. It was being used everywhere and by everybody. Factory owners were giving it to their laborers to increase productivity, it was used in endless tonics, medicines, and drinks (most famously now Coca-Cola = cocaine + kola nut), and so on. You had everybody from Thomas Edison to popes to Ulysses…
> The history of cocaine in the US is quite interesting. It was being used everywhere and by everybody. Be careful with that comparison. The cocaine infused drinks of the past are not comparable to modern cocaine use for several reasons. The route of administration and dose matter a lot. Oral bioavailability is low and peak concentrations are much lower when drinking it in a liquid as opposed to someone insufflating…
Obviously you're right that the absorption is going to be different and a modern coke head with high tolerance likely wouldn't even notice it had anything in it. But give it to a normal person, and they're indeed going to be coked out - in very much the same way that small doses of adderall to non-users can have a very significant effect. The obvious example there being college kids buying pills around around finals.