Look at this video and enjoy upcoming games that are coming in close future using this graphics :
Unreal game engine 4 already is capable of showing photorealistic graphics rendered realtime
That's cool, but show me them doing this while moving the camera in 50 million different directions. That's what happens when you play a game, non-moving or even pre-defined moves like tilting the camera up/down/left/right and moving it (front/back/left/right) reduces the complexity by a ton. None of that even compares to what happens in a real game where they have to rendor from every angle, changes in light, changes in depth with scopes, etc.