> This is only true for mass production, where the set-up costs are spread across thousands of units. For small batches, the cost of automation often exceeds the cost of the batch itself. CNC machines are not magic; they require qualified and competent staff.
This isn't right.
CNC machines aren't magic and they do require skilled people to design for them and operate them.
BUT: they are an enormous advance on capability compared to 30 years ago and are absolutely not limited to mass production. 3D CNC milling is how most prototyping of metal parts is done and can be done to extraordinary precision, repeatably. It was always a low volume technology - it was Apple that started applying it in volume as part of mass manufacture.