Unfortunately, I'm afraid that basic machining skills, even with all the tooling we have at our disposal, are becoming more scarce.
With all the disciplined and well-trained, highly experienced machinists retired from the baby boomer generation, the torch has been handed off to their kids' generation (mine), and not that many people seem to be competent or dedicated enough to get basic things like a thread job right.
I have a personal friend who does thread jobs that other smiths insist he used a CNC on, but he does it by hand. He is very low-key, and does quality, not quantity. I'm not sure if he is taking thread jobs, as he likes to focus on complete custom rifles with an accuracy guarantee.
I had Cross Canyon Arms do a basic AR15 cut and re-crown for one of my retro projects, and it turned out better than decent in many respects. The guy that did it is gone now though, last I heard.