Where is it the only legal drug? Nicotine is often regulated but legal nearly everywhere, and I don't think caffeine is banned anywhere.
I know that caffeine was a bit of competition for alcohol in the period right after it was introduced (some think that enlightenment was caused by this), but I don't think it's like that anymore.
I'm pro legalization for all drugs, but but I'm not going to dispute the fact that booze, cocaine, and heroin are just like cannabis, caffeine and nicotine because it just isn't true. If you don't acknowledge the reality of people's experience when making your semantic arguments then people are going to ignore you.
https://www.ama.org/publications/MarketingNews/Pages/feeding...
here's some BS from the AMA, though.