The cost of materials and transportation and time using the expensive CNC machine will be the major costs of sculpture. Generating the same quality 3D models is at the very furthest 18 months away. And animating and rigging the models and giving them auto-generated RL policies will surely come very quickly next.

If you were going to make a 3D model sculpture you would probably want to just 3D print it instead of using a CNC. In any case sculptures aren't as simple as cutting a 3d form out of a hunk of metal; the variety of materials and techniques is arguably much more interesting than the shape at the end. And the physical nature of it by definition resists the infinite generative shit that AI throws on the internet; there isn't space in the world to store tons and tons of nonsense sculptures, and the cost and time of making them is nontrivial as well.