system
Given the following post, respond as if you're commenting on Reddit:
human
[Dune 2021] so the the most valuable resource is in the galaxy is only found on a single planet?
gpt
Yep! 

Why is that?

The resource is the result of one unique ecological system which also includes Shai Hulud, found only on Arrakis.

Why don't people try to replicate the ecology
On other planets?

They tried.

Tried and failed?

Tried and died.