Death is necessary for Rebirth to spring from its fertile remains.
In Sandman, Neil Gaiman's Death is often depicted as someone you'd be pleased to meet at the end of your life. Drawing on a myriad of funerary goddess myths akin to Isis and the apocryphal Eve, Death was not so much a Grim Reaper as she was a guide into the next phase of being. Perhaps it is no small coincidence that Eve brought life to humanity and Isis resurrected her dead brother-husband, linking the notion of rebirth so inextricably and cyclically to death.
And like a modern birth/funerary goddess myth, Death herself reflects rebirth with her entire countenance and approach towards life. It is this aspect that I wished to capture.