It comes down to the themes and tone the writers want to set in the game. Alcohol fits the medieval fantasy vibe, with its taverns and celebratory feasts, while cannabis might feel more modern or out of place in this kind of setting. As others mentioned, there isn’t a cannabis analog in Forgotten Realms lore. It’s more about fantasy concoctions like potions or magical powders.
By the way, it’s interesting how things like nicotine alternatives in real life, such as
Air Bar Nex, have become the modern equivalent of this “relaxation culture.” It’s a neat parallel to fantasy worlds creating their versions with dream mist and traveler dust.