Summary:
Relates to MC-92772. When the gamerule doMobLoot is disabled, endermen do not drop the blocks they carry upon their demise. This behavior can inadvertently result in block deletion, as endermen sporadically acquire blocks.

Steps to reproduce:

1. /gamerule doMobLoot true

2. /summon enderman ~ ~ ~ {Health:1f,carriedBlockState:{Name:"minecraft:anvil"}}

3. Kill the enderman.

4. /gamerule doMobLoot false

5. /summon enderman ~ ~ ~ {Health:1f,carriedBlockState:{Name:"minecraft:anvil"}}

6. Kill the enderman again

Observed result:
Endermen don't drop their block when the gamerule doMobLoot is set to false.

Expected result:
Enderman should drop their block when the gamerule doMobLoot is set to false.

Note:
It appears that monsters holding items also do not drop them when the gamerule doMobLoot is disabled, suggesting that this behavior might be intentional. However animals still drop their saddles.

Video:
enderman not dropping block when doMobLoot false.mp4