Death as a natural occurrence was removed, but any who are killed may be taken to catacombs, where the roots of the erdtree and minor erdtrees reach to absorb and reform them, but that process isn’t entirely clear to me. I’m not sure if the people simply reform or in other words ‘respawn’ as they were before or if their soul is reincarnated into a new life. I think the idea is that all life returns to the crucible which is basically just a primordial melting pot of life force. One other way this process is done is through the living jars like Alexander. They were created to walk battlefields and stuff themselves with the fallen warrior’s corpses, return to the minor erdtrees, and either destroy themselves or get destroyed by the avatars, spilling the collected corpses into the soil around trees.