Early modern firearms, even though it being a rather nebolous category, suffer the same problems like the early firearms in RPGs and especially in D&D that most if not all their advantages are not modeled by RPG rules.
There are no strength requirements for using bows or damage penalties for low strength characters. There is no fatigue for prolonged combat and ammunition and encumbrance is often ignored or hand waved. And only few DMs will make it hard for an archer to find arrows, even though firearms would have replaced bows for most common people near the end of that era.
When only looking at the combat stats, what RPGs often do, bows would still be superior to firearms although now rifling would be available at great cost to at least get some accuracy. And during the end of that period cartridges would be more common which speeds up reloading.
Also bayonetts would be available bur again the RPG rules hardly make them an advantage considering how quickly you can change weapons. To make up for RPG rules not accounting for the advantages of firearms they tend to make them into armor piercing superweapons which they were not.
Also during that era cannons become much more common and while usually adventurers dont tend to carry them around their existence changed the way fortifications were build. And they can pose a threat to adventurers when they raid a hobgoblin tribe, especially when they are used to fire cannister or grape which turned cannons in very large shotguns.
And here is the main problem with historic firearms in RPGs. Their low rate of fire was countered by one hit usually killing or incapacitating the enemy, but in RPGs this hardly ever happens or only at low level and combats tend to start at such low distances that the enemy can simply walk over to you and start attacking with melee weapons in a single turn.