Unless you're doing it in conjunction with weighing and sorting and outside neck turning for absolute best accuracy from a rifle , KDX, I don't think it does a thing on it's own.
I used to shoot 10,000 + CF rifle rounds a year and half the time I wouldn't even clean primer pockets.......neck size-prime-load-go. A lot of the time I never lubed cases either, but that bad habit caught up with me. The critters I shot never noticed the difference though.
None of these processes hurt your accuracy, for sure, but neither do they necessarily help it in a standard weight sporting rifle.
My point is that we COULD do a lot less prep work and still end up with perfectly functional and accurate ammo. My motto used to be "minimize loading time - maximize shooting time", you don't get to be an outstanding shooter sitting at a loading bench, chamfering flash holes, weighing brass and turning necks.
I would challenge a bunch of you guys out there to take a known sporting weight rifle and load that shoots a consistent group of 1" or a little less and try this with it;
Take some fired but as yet unprocessed, in any way, brass.
DO NOT trim.
Run it through the sizer and only partial size for 3/4 neck length.
DO NOT clean primer pocket, or tumble or anything else !!!
Quick wipe off lube (if used) with rag and prime.
Take your known load and set up thrower and THROW (do not weigh) 20 loads.
DO NOT chamfer neck inside or out, seat bullet to known overall length.
DO NOT check COAL after setting up die and seating first bullet.
Now go out and shoot groups with these 20 "SLAPPED TOGETHER" loads and tell me if you can measure a difference in groups.
This is exactly how the factories do it (except for dirty primer pockets, and they don't seem to matter) and I have seen numerous rifles shoot well under 1" with factory ammo lately.
I think you will be surprized !!!
This is how I used to load for a long time, and I killed more by 10 times than I missed, and this includes shooting out to 400+ meters on crows, gophers, jackrabbits and badgers and anything else that moved and caught our attention.