Saying everyone was 'coked out of our mind' seems a bit far fetched. Yeah there were niche products using coke and consuming/exporting it was legal, but historic production numbers from the period are a small percentage of modern production numbers even considering the populations were lower.
Cocaine exports then vs. now: early 20th century legal exports at their peak(1921 - 30 tons) were roughly 1/20 to 1/30 of current illicit production.
At the time most coca production was for local consumption, far less was aimed at the international recreational market.
https://www.sciencedirect.com/science/article/pii/S037687169...
Not to say there were not other drugs on the market, like Morphine
On the other hand 7up used to have lithium in it. (though that was later in the 20s)
It wasn't niche. In the US cocaine was available just about everywhere - pharmacies, grocery stores, mail order, being used (in high quantities) in dozens of beverages, and so on. [1] By the time of its effective prohibition it was seen by many as the largest health crisis in existence.
I suspect the numbers you're citing are subject to a large number of biases - different demand/utilization in different areas, considering mass without purity, poor recording keeping and/or off the book deals, and so on.
[1] - https://pubmed.ncbi.nlm.nih.gov/8473543/