What makes the 1911's more accurate than some of the other pistols out there?
Nothing, they are anything but in their stock form and require alot of tuning and adjustment like anything else. From there it's the shooter that needs tuning and adjustment to make the pistol do it's best.
I've owned a junkyard pile of 1911's over the years and none of them were any better than my CZ's and I have some wheel guns that just plain spank them into submission as well.
This. I had to put a Kart hand fit barrel and bushing in a Desert Eagle 1911 to get it to shoot as accurately at 25, 50, and 100 yards as a stock P-09, P-10F, P-10S, or P-07. I had to add CGW bushings to a 97B"E" and 75B to get them to shoot as well as a stock P-09. But I had to add Sugru and JB-Weld to get my hands and fingers to fit nearly all of the above before I could shoot them all well. There is a lot more to "accuracy" than the mechanical clearances. The match between the gun and the shooter makes a big difference. The 75B design fits a lot of hands very well out of the box. So do a lot of 1911's. I had to do a lot of work on the polymer guns and triggers to get a perfect fit for my hands/fingers. But, mechanically, all the late CZ polymer guns seem to be excellent, in other words, as good as my hand fitted 1911 at less cost.
So, the "most accurate" CZ for me is a P-09 with some grip modifications. Second is a 75B with a CGW 10x bushing. A 97B"E" is more than $1,000. Knowing how good the Kadet is on a 75B, that alone would have me leaning towards a 75B with a 10x bushing, so that I could add a Kadet kit later on. I've never owned any of the competition oriented CZ's and probably never will. The service pistol versions seem to be good out to 100 yards, LOL. The best day I ever had at 100 yards was with a P-10S, however. That says something for modern machining and design. The striker pistols grow on you after a while.