What are some ways that stop players going all-out when it comes to hoarding?
In Subnautica, the very first item that almost all players tried to hoard were acid mushrooms:

Those of you who've played know very well that after about 2 hours (some of us are stubborn) of gameplay, you eventually decide to poop them all onto the floor.
This was EXTREMELY effective at teaching players to only pick up what you actually want.
I think there are 4 things that really helped to drive the point home:
- limited inventory space
- (most) items do not stack
- other stuff we actually need to carry
- a legitimate cost to increasing storage capacity
It also helped that you encounter this really early in the game.
As inconvenient as it is, I believe these limitations could help Ashes' players be more tactical about what they pick up. I think it'll also encourage trade - people will want to get things out of their inventories faster.
On the other hand, it won't prevent players from slaughtering anything that moves for exp.
Any other games that punished you for hoarding?
EDIT: To be clear, I'm not concerned about hoarding for monopolization, I'm concerned about EVERYONE having 300 rabbit pelts and therefore nobody ever trades rabbit pelts.