User blog comment:Xilinoc/Ch. 686 - Death & Strawberry (End of Bleach reMIX)/@comment-5303512-20160819010913/@comment-24769684-20160819013546

I think the way life and death works in Bleach is that there are two realms (Physical World and Soul Society), and death is the crossing over from one side to the other. So basically people exist in an endless loop of two stages of life, gaining new identities once they cross over from Soul Society to the human world.

The goal Yhwach stated at the end was to create a world without the barrier of death between the two realms, where people just lived forever as a single person I suppose. Man was that reveal shoehorned in.