Fair enough, but a key component of addiction is the detrimental effects of the addiction on the individual, and the people they associate with (from the family to society at large). Caffeine consumption, even in some level of excess, isn’t going to have nearly the same deleterious effects as actual drugs of abuse do, so even if an addict does end up having several hundred milligrams of caffeine a day, if that’s all they’re using, they’re still infinitely better off than before, as long as they don’t add more stuff in later and keep escalating.