^{From MCPE-65816:}
Mobs now can pick up items in the latest nether beta. The problem is that netherite armor is not the highest armor for mobs. If a mob has netherite armor and then the player drops diamond armor out, the mob will pick up the diamond one.

Steps to Reproduce: 

1. Summon mobs (zombies or skeletons).
2. Drop netherite armor to the ground and wait for one picks up.
3. Drop diamond armor to that mob who has the netherite armor.
4. You will see that diamond armor overwrites the diamond one.

Observed Results:
Not netherite is the strongest equipment for mobs.

Expected Results:
Netherite should be the strongest equipment for mobs that picks up items.

You can see this video for easier understanding: https://drive.google.com/open?id=1Yk-a72B8tLuy_ESJi2AqbSFWO-GnrZMA

Original Description:
When mobs wear Netherite gear, they will change to diamond gear if picked, and throw those netherite