Name a song, Al. You are missing one thing though. The only thing that could make use of the available bandwidth right now is AGP texturing, but nobody is doing that since most video card makers are putting plenty of RAM on the card and AGP texturing is much slower. That doesn t mean that 4X and 8X won't be important in the future though, they should increase in importance as the amount of detail in games and apps increase. It nice to have a problem solved before it becomes a bottleneck for a change.
Life is complex.
It has real and imaginary parts. Current graphics cards uses methods that allow them to store textures in local memory and, as a result, do not require the bandwidth that AGP provides. Perhaps I should state that differently. It's not that they don't need it, but that it's not enough. It has been much documented on games like Quake 3 that fps tops out at high resolution due memory bandwidth limitations.