*Spoilers* The Past and After the Endwalker MSQ End

[Lurina]

Yeah, this is absolutely the angle. Tactically, Venat's plan was ironclad (or at least, as ironclad as it could get). Ethically, it was questionable.

To a point on an 'ironclad plan' though, you have to be willing to take the authors' word on it. Actually showing to exact lengths that a plan will be successful--and more successful than any alternatives--would just get tedious and boring, as well as lessening the impact of the actual characters enacting said plan, not to mention being basically catnip to people who value being smarter than the story over enjoying it. You kinda have to accept whatever groundwork the story goes through to confirm 'this is a good plan'.

Emet-Selch specifically saying that Venat's plan worked when his wouldn't have is part of that. Emet-Selch is a trustworthy adjudicator of Plan Goodness here, both as someone who initially opposed it and someone with a uniquely wide amount of knowledge of the situation, so if he says that it's the only one that would've worked then we can safely assume that is indeed true.

This sort of narrative economy argument only really works when the narrative is, well, economic - when there aren't unaddressed threads that seem to contradict what it's trying to tell you is self evident.

The writers didn't have to put the line from Emet where he suggests the convocation had special means of telling truth from lies. They didn't have to leave the implication that Venat's plan evidently is not ironclad by making the plot of Shadowbringers predicated on it having gone wrong in another timeline. The issue is not merely an absence of facts supporting the premise, but the presence of facts counter to it that require the audience to find their own justifications for dismissing.

The more controversial a plot element, the tighter the plot has to be to get people to accept it in good faith, and "cultural genocide was the right call to save the world" is about as close to maximum controversy as you can get. I think the fact that these forums, the comments on Venat's entry in the JP character poll, and pretty much everywhere else the story is being discussed are filled with people expressing discomfort or irritation with it self-evident proof that the writers didn't quite make it.

That might change with the post-MSQ content, mind. But it's at least true for the time being.