That's exactly what I was thinking. The 1911 barrel floats all over the place. If you put a tight target bushing on it and make the rear lockup super tight, then you lose reliability. Then there is slide fit. A custom gunsmith that takes a lot of extra time and effort can make them shoot like target guns but your basic stock 1911 isn't all that accurate. Actually when I was growing up, lots of oldtimers would claim you couldn't hit a barn with one. From inside the barn.
A lot of that comes from the WWII-era pistols, made to loose enough tolerances that all parts, regardless of maker, could interchange, and then those guns being in service for thirty or more years.
The USMC had guns, in the '80s, with verified round counts of over 300,000, so those guns might be a tad loose. How many grunts received much pistol instruction, anyway?
Modern, mass-produced "1911" pistols are often built to tighter specs than the wartime guns, and even a $600 pistol can be quite accurate. Most "inaccuracy" in handguns is generated by the shooter.