It's good enough if you are proficient with it. Saying that one needs to know the .380's limitations is true as it is for every other handgun round. You should know what any round you use is capable of. And I mean by actual practice and real world shooting.
The main thing with any round is hitting accurately with consistency under any circumstances which only comes from practice. Practice and more practice is the only way you can be proficient with any handgun much less a very small one like a .380 or small 9mm etc.
Please don't anyone take this personally but imo until someone has at least a couple thousand rounds of serious practice they are likely not very good with a handgun yet however they have significant experience. Not enough to have that much of an advantage on the average bg though. I will add though that a lot of dry fire practice can make up for less actual rounds being fired. Someone who is good with a .380 can beat the average guy with a 9mm. There are people I'd rather have help me using a .380 than most anybody else with whatever handgun.
To me the .380 good enough because I will carry it when I would have left a larger gun behind. It's good enough to me because I am confident that I could use it to save my family or someone else's life under many circumstances. Any gun can also be used to help keep the bg away from you enough to allow for an escape. A bg can walk right up to you if you don't have a gun but if you shoot at them they tend to want to avoid being hit. Even a .22 can be helpful here. Most of the time though a larger easier to handle 9mm or better is more comforting.
So yes a .380 is good enough if you are.