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Well no, since they exist, and they sometimes affect the cast directly by shooting at them, they're just offscreen.
Genshin Impact: in Navia's story quest, the Arc Villain Romeuf, one of Navia's father's former allies, is only mentioned in the background; you (the Traveler) and she only deal with his lackeys and Colter, one of her subordinates who reveals his allegiance with Romeuf.
Probably sth like this?
A work that features a central conflict against someone or something (foreign country, aliens, zombies etc.) as a backdrop also has a conspicuous absence of them, focusing on the antagonists on their own side.
e.g. A work set in the trenches of WWI (on either side) that never shows the enemy, only the occasional bombardment but never any soldiers, and most of the conflict is between soldiers and officers, deserters and loyalists, two soldiers who hated each other before being conscripted into the same battalion, etc.