I think if I had to pick one thing that a CNC router can do unquestionably better, faster and cheaper than a human can do it, it would have to be the cutting of ovals and other elliptical shapes ....
I tried a few back in my early days of carpentry and custom sash work
and they are about impossible to do easily and gracefully by hand ...Here's a link to a blog post I wrote about it ... Custom oval cuts of any type are extremely easy to do with the cnc ...
copy and paste it to your browser