You would need all nodes to hold almost all geometry, even when you achieve this, you would have to cut the screen into 10,000 pieces of pixels, and then trace

You would need all nodes to hold almost all geometry, even when you achieve this, you would have to cut the screen into 10,000 pieces of pixels, and then trace each one individually. Some of these small ares would finish much faster than the others, and it would be hard to move them to do another job (or expensive). But that's from my simple understanding, possibly there would be other problems too...