
In vanilla Minecraft, whenever a mob (such as a Zombie or Skeleton) picks up an item off the ground, it is permanently marked as persistent. In modded environments or long-running servers, these mobs accumulate in underground caves over time, permanently filling the server mob cap and contributing heavily to entity lag.
Despawnings fixes this problem by allowing mobs that became persistent solely from picking up ground items to naturally despawn again, while safely dropping any collected equipment on the ground so no player items are lost.
A lot of mods like this already exist. I know. This one fits my purpose more and generally works better than the other ones. (also doesn't require a dependency)