I don't buy the notion that eaten, lived in etc. is merely a non-essential luxury. I find much of the art/entertainment etc. I see personally useless or worse but ... I think the fact that the impulse to create and consume these things is so innate in human beings suggests that is vitally important in some way. Religious people apparently tend to live longer as well, but you can't eat that either. 

Now maybe you're only referring to CGI and not art/culture in general. In that you would probably be correct since mankind existed fine before computers were even invented. Still, they are increasingly the medium of artistic expression and therefore no less valid than other mediums IMO. Sorry but it just seems like too simplistic a view. By extension, you could say that a packing crate will do just as well as a house and we could all eat algae and wear garbage bags. Yeah, we could but where's the fun in reducing everything to the LCD :-) Apologies if I misunderstand the point.

"Democracy is a pathetic belief in the collective wisdom of individual ignorance." - H. L. Mencken