EFFECT, n. The second of two phenomena which always occur together in the same order. The first, called a Cause, is said to generate the other-which is no more sensible than it would be for one who has never seen a dog except in pursuit of a rabbit to declare the rabbit the cause of the dog.
If you look at the requirements for just one piece, like art, from one generation of games to the next, it will change radically. You need people who are adaptable because the thing that makes you the best in the world in one generation of games is going to be totally useless in the next.