>>723822098
I think the problems with fully integrating gunpowder and early firearms into a fantasy setting are mainly 2:
>balance with other weapons and armor
It might be difficult to make a firearm feel balanced in comparison to other weapons in vydia; it is usually either too strong, too weak, or it just isn't distinct enough from a bow or a crossbow.
>slippery slope towards other firearms later on
If the setting adds firearms, it may become slippery slope towards more advanced firearms and gunpowder tech, specially considering how in fantasy worlds things tend to be technologically advanced in some areas, but not in others. The point automatic/fast-firing weapons are introduced in the setting, it's over.