Comparison:
Skinning and quartering body with damaged kitchen knife
Yields about 69% steaks
Skinning and quartering body with pristine stone knife
Yields about 99% steaks

Opening cans with damaged kitchen knife
Yields about 70% content
Pristine stone knife
Yields about 100% content

Pristine kitchen knife can be used a few dozen times

Pristine stone knife can be used about a hundred times. It literally stays "pristine" for AGES!!

Something is way off. You've switched the tables or something.

A stone knife would never stay sharp even 1% as long as a metal knife.

This is why you use a stone to sharpen an iron knife in real life! Because metal is more durable than stone! How come this is not the case in DayZ, but a stone knife is more durable than a high-end blade?

To add insult to injury, the stone knife is immediately available and only takes 50% of the storage space (which doesn't really make sense either)

Please fix this, it is so over the top!