the lightest modern bows for hunting deer have drawstrengths of more than FIFTY POUNDS! And medieval warbows had even higher drawstrengths (upwards of 150+ lbs). That is not something you can brush off so easily in the context of fantasy. (certain things still must obey the laws of physics) By comparison, guns are simpler to aim and fire, as you don't have to hold a ready shot while aiming. (The reason guns replaced bows on the battlefield is because while guns are more mechanically complex, they are significantly easier to use.) So yeah, it is a big deal.