Using any damage type in /damage damages a targeted item entity.
This makes sense if you use a damage type like cactus or lava, but it even destroys it if the type doesn't make sense for items such as fall, drown, or fly_into_wall.
Steps to Reproduce:
Throw an item on the ground
Run a damage command using a damage type that wouldn't normally affect items.
Example:
/damage @e[type=item,limit=1,sort=nearest] 10 minecraft:fall/damage @e[type=item,limit=1,sort=nearest] 10 minecraft:fall
Can confirm item will take damage, 1.20.2
Ran following command:
Result