The Alchemy Cathedral lured all living alchemists involved with human subjects underground under the pretext of agreeing to transport living materials, separating them from living alchemist factions like the Life Essence Society that do not involve humans.
Then, with a single stroke, they cut off food, water, and supplies. The Alchemy Cathedral planned to completely trap and starve the evil living alchemists to death underground.
As for why they chose to trap the evil living alchemists deep in the Fissure Corridor rather than anywhere else, Noland Lee thought it was a matter of the size of the "bait."
If the bait wasn't big enough, the evil living alchemists wouldn't naturally take the bait.
Only bait on the scale of the Universal Metal Powder Collection Device would make the living alchemists knowingly walk into a possible trap.
