> Moore's law is exponential, which is where the "simulate a brain" predictions have come from.

To address only one thing out of your comment, Moore's law is not a law, it is a trend. It just gets called a law because it is fun. We know that there are physical limits to Moore's law. This gets into somewhat shaky territory, but it seems that current approaches to compute can't reach the density of compute power present in a human brain (or other creatures' brains). Moore's law won't get chips to be able to simulate a human brain, with the same amount of space and energy as a human brain. A new approach will be needed to go beyond simply packing more transistors onto a chip - this is analogous to my view that current AI technology is insufficient to do what human brains do, even when taken to their limit (which is significantly beyond where they're currently at).