CNC can do 95+% of the work in less than 5% of the time, allowing humans to do that last little bit(if it's worth it) and focus on important things like improving the entire system.

Do people actually enjoy the numb hands, sore backs, picking shards out of skin and hours and hours spent grinding out the bulk metal before you even get to the part that requires brainpower?

It's not one or the other; it's both focusing on what they're better suited to. S/F....Ken M