The reason the 1911A1 has survived so long is a rare combination of things: a .45 ACP will stop even a hashish-hopped, leather band wearing Muslim fanatic, something a .38 was far less likely to do (Philippine Insurrection); it could survive and function in extremes of cold and heat, wet and dusty dry; it almost never jammed; it had a barrel end safety, a grip safety, a slide safety, a sear disconnect, half cock safety, and firing pin safety.
I remember reading about ten years ago that during Operation Iraqi Freedom Iraqi soldiers and jihadi mercenaries strung out on methamphetamine and pain killers would sometimes require being shot with at least four, five and sometimes six rounds from M-16’s and M-4 carbines before they’d go down but on round of .30 caliber from a mini-M-14 as one soldier said ‘’put their dicks in the dirt every time’’. On such targets the M-9 Barreta was almost useless.