Levistus's_Leviathan
5e Freelancer
Well, like I said, that's largely because you have a better chance to actually kill someone from range with a gun than with a sword. If someone was standing 60 feet away from me pointing a sword at me, I would get the heck out of there as fast as I could, and I'd probably survive. If someone was standing 60 feet away from me pointing a gun at me, I would still try to run, but I'd have a lower chance of survival because the primary benefit of firearms is that they're lethal at range and fairly easy to use in comparison to other ranged weapons.That's because relatively few people are shot in the chest or head. Hips, arms and legs (and even abdomen) shots are generally not lethal presuming urgent medical care is available.
However that also applies to cutting and stabbing injuries as well.
Your chances of surviving a 9mm or 5.56 round to the head or chest are negligible.
I can assure you, if I had a sword, and my opponent pulled a loaded single shot .45 handgun on me, I'd call off the attack.
A dude throws a sword at me from 60 feet away, that's likely his only sword, and I'm going to survive. If a dude shoots a bullet from a gun at me, he has a decent chance of hitting me and doing lethal damage, and even if he misses, he almost definitely has more bullets.
There's a reason no one uses swords and other weapons in modern warfare and combat anymore, because guns are easier/faster to use than other ranged weapons, and the farther away you are from someone that's attacking you, the less likely they are to hit. D&D can't properly model this, because your Armor Class and Hit Points are the same whether you're 5 feet away from someone with a hunting rifle than if you're 80 feet away from them. D&D doesn't properly model this, even when accounting for Long Range, Cover, and other factors (especially if you just take Sharpshooter to ignore both of those things).
Guns are deadlier because they're more difficult to dodge than swords, they have a much longer lethality range than swords, and are easier to master. I personally use the current official D&D firearm mechanics as written, and I can understand arguments both for less damage dice and for more damage dice for both firearms and swords, but D&D just isn't good at modeling this (and isn't meant to). Slings should have a higher damage dice than 1d4, darts should probably do just 1 damage, crossbows should take forever to load (as should renaissance firearms), and people shouldn't just pass out when they drop to 0 hit points. However, D&D isn't modeled to be realistic, it's modeled to let its players have fun. (That is not to say that it can't/shouldn't improve, but I just don't think that this discussion will have any constructive conclusion.)