Sleep and Evolution

Sleep is actually one of the reasons I do not believe in deity, next to dandruff. Whatever sleep does that is good for us, and I know sleep feels good, too, could have been accomplished without the act of doing nothing for 1/3 of our lives. Imagine a world in which just drinking water did whatever sleep does that is good for us. But you could say the same about evolution, right? Could evolution have done something else to accomplish whatever good sleep does for us? When I think of answering this question I think of the giraffes neck, and nipples. In the giraffe's neck, if I'm not mistaken, there is a nerve that that actually does a completely unnecessary loop, but the unnecessary loop was a byproduct of the evolutionary process. I don't think I can explain it as well as this video:

Nipples are also also a byproduct of genetic processes. Certainly, an omnipotent god could have made a universe in which males did not get nipples. But he didn't for whatever reason, and in biology we find that it's a genetic byproduct of gene activation in the development process.