Yes, and for thousands of years we killed each other will bows, arrows & spears. However, I don't recommend those for a CCW today.The Brothers in the 'hood been killin' each other with 'em for decades. I've seen it.
The problem with "mouse guns" as a primary CCW is that people carry them for convenience and not due to any profound belief that they are the best choice. Therein lies the problem. The typical "mouse gun" carrier retorts that "Well, any gun is better than no gun!". Yes, but that's not the point. Obviously, the person feels something warrants the carrying of a handgun as they are doing as such. That is of course unless they reply "Well, the odds of me being in a gunfight are infinite!!". Granted the odds are long, but if they really believed that then they wouldn't even carry a gun in the first place, right?
Yes, many people have died from .22, .25, .32 & .380 rds. However, that is usually hours it not days later and after they have riddled the person who shot them. We are trying to STOP bad people and not merely kill them. Decades of statistics show that one is far better served with a service grade caliber weapon utilizing modern defensive JHP rounds and even then all bets are off. Unless of course you're Robin Hood with a longbow.