When players die, their items are placed into a single bundle that cannot be picked up by anyone for 60 seconds (time can be changed with gamerules). The player that died can sneak to pick the loot bag up early and it will be teleported to them if it is within 8 blocks. This feature will not work if keep inventory is enabled but it also doesnt conflict with it. The loot bag never despawns and cannot be destroyed by explosions, lava, or in the void.
Use "/function death_loot_bags:gamerules" and click on whatever gamerule you want to change to edit it. #death_loot_bag_pickup_delay is in ticks (0.05 seconds).
