Mostly I'd guess they don't have the fabrication capability to do this. Nikon as far as I can tell doesn't make any of their own sensors. Canon doesn't make the

Mostly I'd guess they don't have the fabrication capability to do this. Nikon as far as I can tell doesn't make any of their own sensors. Canon doesn't make the sensors in their cheaper cameras (from what I can tell from googling, and my own teardowns). Sony does, and a number of smartphones use Sony sensors.