I may have missed it but there's another consideration from my viewpoint and that's accuracy. These tiny .380s are more than difficult to shoot even with defense grade accuracy at more than a few yards. They're also so uncomfortable to shoot that we tend not to practice with them. I'm guilty of this with my LCP which is there but which I tend to not practice with since it actually pinches my hand in use.
To see what I mean, set up a target at 10 yards and try to hit it with your LCP or Kel-Tec or whatnot. I find that to be near impossible where doing so using even a subcompact such as a Shield is simple. While I'm on a bash, I'll also say that IMO, the Shield, for all it's great, makes no sense in .380 except for those who are fantastically recoil sensitive and/or cannot rack the slide on a 40 or other major caliber pistols of that size. Why use a .380 when it'd be just as easy to use a 9 or 40 or even 45 two of which have vastly less expensive practice ammo plus better defense loads.
I bring up accuracy since it's important, IMO. In the case of need, I wish to hit the bad guy but not hit the good guys which is easy at defense range for the aforementioned subcompacts such as the Shield class weapons but is more than problematical with the tiny .380's. Consider: you're in a store. A goblin shows up to rob the place shouting he'll croak everybody there so you having your CCW, swing into action to prevent him from croaking you and the others. You shoot at him but with a tiny .380 you end up wounding the clerk and an innocent shopper. Sure the goblin is legally liable for that but how'd you feel? I know how I'd feel - terrible.
In sum, the best I can say about the tiny .380's is they're better than two things: a .32 or nothing and that's not saying much.
It's a lot better than nothing and I've found my LCP to be pretty accurate even out at 15 yards. I do agree that 380 doesn't make sense for most people once the gun gets up to the smaller 9mm size class, because at that point you may as well have a more powerful and economical cartridge. But for a little pocket pistol it's a great caliber and I frequently carry it when the alternative would be not having anything.