CNC is not a machine, it is a protocol.
You can take a lathe and machine a part with it by turning the hand dials. If the operator does not make any mistakes by dialing in or out too far, if his machine is solid, the part comes out like he wants.
You can then take that lathe and set it up for CNC. Then you write the programs (great! a new skill required!) on the computer to do what you just did manually, load your piece, and if everything is written perfectly and set right, turn the program on, and the piece that is machined would be basically identical to the one just made. If you were making just one part, it would probably be faster to make just one manually (if not too complex) rather than do the programming and use CNC. If you had to make 1,000 parts, it would go much faster using CNC, and you have the power of repeatability of a computer. A person will eventually make some mistakes if he had to make 1,000 parts, at which point he keeps making some over and over again, or he lets a few minor flaws through.
You can apply the same thing to an inlay machine. An inlay machine might have 3 dials on it, one for depth, one for left/right, one for forward backward. You can use this inlay machine to cut a pocket out of a cue, or cut a part out of an inlay strip. After the pocket is cut, it might need to be cleaned up by hand, and modified to get super sharp corners. The radius of the cutter is paramount on how sharp corners will be. After the part is cut out, it might need to be cleaned up by hand, and modified to get super sharp corners. Then, hands glues the part into the pocket.
You can then take the inlay machine and set it up for CNC. The same machine with the same cutter can now be used to cut out the same pocket and the same parts under computer control. The same manual modifications would need to be done to the pockets and parts afterward, and the hand gluing done.
The CNC buys you repeatability with perfection, barring a machine failure. It does what you program it to do, right or wrong. Barring machines and cutters wearing out, it is tireless and basically a helper.
CNC also buys complexity. You can program complex movements that a person cannot perform manually, let alone repeat over and over again, to inlay complex shapes and curves. Templates can be used for the manually controlled machine, but then someone probably uses CNC to make the complex template....and you need a new template for every new complex design.
CNC is a protocol derived from computer code used to control a cutter in lieu of a machinist's hands used to control a cutter via handwheels (or the like). All other operations, such as deburring the part, cleaning up the pocket, gluing are still done by hand.
Kelly