I always thought 380 was for people who wanted the recoil of a 9mm with a slower and smaller projectile
but maybe these new-fangled non-blowback pistols are more comfortable than the 380's I tried in the 90's.
The reality is that we don't have enough publically available evidence to confirm without a doubt that it will either ALWAYS or NEVER work for anything small enough to work in a handgun. There are too many variables - lighting, distance, ammo QC, tripping hazards, bone density, and anything else you can imagine. If you're confronted by a 400 lb bad guy, 9" of penetration may not make it to a vital organ
... The reality is that you have to find what variables you are going to care about and maximize those.
I prefer a round that throws a heavier bullet as faster speeds with a pistol as many extras in the magazine as possible, but not everyone on the internet can be right like me.