The only way it will happen if a new player comes into the market with a truly new technology. Think the first iphone or the Tesla 3.
It won't come from Nvidia or AMD though that's for sure. They will continue to milk us like the cows we are.
Yes we do need a third contender ....life was so much fun when we had more than two vendors .....but who would it be who is left some one new /old .....i would love to see samsung ,nec ,matrox anybody come into play really. who is still going no one is strong enough is there?
or is it there is not much pennies to be made in gfx industry any more