It's situational.
For example, if you are in the Yukon and you are a fur trapper as your profession, and you will be out and about in the woods for a season or two with your dog(s), you would be completely insane to go without a gun. The gun will reduce your risk of starvation significantly, it will also reduce your risk of death by bear.
If you are a child in a city, then carrying a gun increases your risk of accidentally shooting yourself, it also increases the risk of accidentally shooting somebody else.
In general, it's unnecessary to carry a gun in areas with medium population density.
In areas with very high population density, it's probably a good idea to carry a gun due to the overcrowding causing peoples attitudes to run hot. (Inner cities that have high crime)
In areas with very low popluation density, it may be a good idea to carry a gun to keep yourself protected from nature/elements. (middle of nowhere where you may be at risk of getting eaten or starving to death)