To be brutally honest, with all the small framed 9mm pistols out there I find no reason at all that anyone would want to carry a .380
Nothing "brutal" about your comment.
Individual perspectives and experiences can vary a bit, though.
That's the reason I got rid of my Beretta 84. I could get a compact 9mm that held as many rounds and was as easily carried as the .380 compact. Or, I could carry my Star PD .45 compact.
The thing is, I couldn't find any diminutive 9mm pistols,
that I wanted to own & carry, which are as small as the LCP or BG380. The LC9 & Shield 9 I recently tried on our range just weren't nearly as small as the LCP (or BG380). Neither was the PM9 I tried. (I've looked at a Nano, and it's not as small as the LCP.

)
Even if I buy a Shield 9, the LCP will still occupy a place in my retirement collection, solely for reason of its overall size and ease of concealment carry in many of the situations & circumstances that matter to me.
I never expected to own, carry & use another .380 pistol. Not at all.
Well,
Never Say Never, I suppose.
"Ballistic Effectiveness" is a subject that involves too many shades of grey for anyone to offer a
definitive answer that will ever satisfy everyone.
When I was younger, I used to be one of those guys who thought that
only a .357 Magnum, .44 Magnum/Special, .45 Colt or .45 ACP were "worthy" defensive calibers.
As a young cop I carried an issued .357 Magnum on-duty and either a "full-size fighting revolver" (remember when that appellation was popular?

) chambered in .357 or .44 Magnum off-duty, or else my .45 Commander.
After a career in LE, and having worked as a firearms instructor for over 20 years, my opinions have changed and evolved over time. I own several 9's & .40's, and a slew of .45's (barrel lengths of 3.25", 3.5", 3.75", 4.25", 4.5" & 5"), and I still have revolvers chambered in .38/.357, .44 & .45 Colt ... but the most commonly carried guns are my small 9's/.40's & my 5-shot J's.
Until I picked up the LCP, that is. Now, it sees an increasing amount of use. I
would not carry it, however, if I couldn't shoot it accurately, controllably & effectively. That's
me.
I also wouldn't carry it as a "duty gun", as I recognize its inherent caliber limitations.
I don't shill or proselytize handguns, handgun calibers or ammunition. I work with what someone is either
required to use, or
chooses to use ... and we focus on training, skillset, experience and mindset.