This is not my field, but I'm...socialy adjacent? and my understanding is that we grow big crystals of silicon because that's the mature technology, but then there are multiple cutting & polishing steps that add to the cost.

We want small pieces of thin wafers, but we grow huge crystals and then slice them into wafers that we then have to cut up. With vapor deposition diamond you can remove a lot of those steps by growing what you need, say a grid of chips of the desired dimensions directly on a carrier substrate.

As I understand it.