system
A chat on subreddit /r/NoStupidQuestions
human
Alcohol because of how cultural acceptable it is and how it's readily available, relatively cheap as well, other drugs are likely easier to get hooked on but you have to interface with a whole criminal scene, so in that way it's harder to get access, which is the first step to addiction
gpt
And it’s the only thing that can kill you, other than benzos, when trying to stop.