While you certainly have a point in terms of wrestling with the uncanny valley, you are missing an important element in your “computer can never…” argument: you are ignoring the human element that makes the computer do everything.
CGI is created on a computer, sure, but that computer – it’s hardware and software, the models, engines, textures, animations, etc – are all created by artists and computer scientists. As these groups of talented people learn more and develop new ways to replicate what our eyes see and how our brains react, their CGI creations improve. You should read up on everything that goes into CGI – not just the cookie-cutter behind the scenes footage on dvds, but the actual science behind it all.
A perfect example is the computer advancements done on Gollum in The Hobbit: they actually studied/analyzed how light passes through each layer of skin and tissue, how and where different wavelengths are absorbed and/or reflected based on countless variables of the skin tone/thickness/location/light intensity/type/color, etc. They then used this to create a software engine that replicates those real world properties. Those efforts are a HUGE reason why Gollum looks so much better in The Hobbit.
The short version: It is incorrect to think that the uncanny valley is insurmountable. There are artists and scientists studying how EVERYTHING works in real life and figuring out how to recreate it on the computer in order to trick the human eye and brain. Being human themselves, they know what to look for in order to succeed. The quality of CGI improves exponentially based on these people’s knowledge and techniques. The more they learn/create, the smaller the uncanny valley becomes.
The problem is not that the uncanny valley is impossible to overcome; the problem is production companies do not give CGI studios the time nor the money to make advancements as fast as they otherwise could.
