Death produces focus and causes change. Without death (whether symbolically or actually) a game has no purpose, no reason to pick up the gun and no sense of motion. Without death there are no wins. There is only activity.
It may be as visceral as a bloody spatter, as ordinary as a rotting crop or as abstract as a penalty shootout, but death is everywhere in games. Death frames a game. Artistically as well as functionally, death is right at the heart of what games are.