The 1911 platform is no longer made by just one manufacturer.
Neither was it for any of the military contracts. In WW2, there were five. The difference was that they were built to spec, and every part was checked during each step of the production and assembly process with standardized gauges. Sadly, this no longer applies. Everybody and his uncle has jumped into the market, trying to get a piece of the 1911 pie, and many of them seem to make it up as they go.
One of the tests during the WW2 production was for two pistols to be randomly chosen from each of the contractors...the pistols disassembled and tha parts tossed into a box.
The armorers then assembled 10 pistols without attention to parts selection, and the completed pistols were then tested for function, accuracy, and reliability. They all passed.
Today, most of the manufacturers understand that they're essentially producing a toy...or a pistol "Just like the one my daddy carried when he went ashore at Tarawa" and they know that the majority of them will probably never see more than 50 rounds a year...or in a lifetime...so they don't have to be as reliable under adverse conditions as their military forebears. Men aren't going to drag them through the trenches or the sand and depend on them to save their lives.
I recently had a conversation with a pistolsmith who worked for a time for a well-known 1911 clone producer. I won't call any names...but these are his words, verbatim.
"Johnny...Honestly, I can't get'em to hear me. They're building these pistols with a maximum of about 1,000 rounds in mind because they know, and have stated that the average buyer won't shoot one much more than that in 10 years."
His words. True story.