have to agree that it depends on your application... but be remind we're in 軍事討論區
so my 2 cents tells me that Gov't/police force/agencies prefer 9mm/40sw mainly due to the $$$, capacity, training cost, ammo choice, etc.
while SF/Elite uses .45, I guess it's because it's subsonic and easy to suppress when it needs to be, Seals/Delta still mainly uses 9mm nato rounds
(please correct me if i'm wrong)
but for a average person's general use, why is this a thing anyway? I mean just choose whichever you prefer. choose whichever you're comfortable shooting with and get a lot of training with it (this is where the context cheaper rounds are more favorable).