Black and white duality can be complex.
FF's more like a mix of Marcus Aurelius's Stoicism and Immanuel Kant's Transcendental Idealism.
There is depth to that, it's just a beneath the surface of the reasoning.
FF has a history of being aware of any questionability, but rebukes it with a stoic response. Fully aware of its stance.
With players, I'm pretty sure CoD or other games that don't narrative for their main game focus is actually a better argument for Nihilism.
Or most other MMO's where you kill massive amounts of sentient beings without any backstory justification.
Morally grey stories can be done well.
But they're usually surface level deep for psudeo-philosophers to think their thoughts are provoked, but usually over the same tried issues.
It's a cop-out because like more simple black and white stories, it doesn't acknowledge the difference between a priori and posteriori heritage of morality.
The silent protagonist should not be taken as a person with choices.
They are more of an agent of the world.
It's precisely because these games still use a silent protagonist, without choice, that it emphasizes a deterministic but non-nihilistic(usually brought up, such as with the Gaius Baelsar) narrative.
In these cases, there was never any real choice anyway. It's an illusion.