What's the point with that quite lackluster story in Endwalker?

[Jandor]

It's because they literally did not know of the threat's origin whatsoever, so like how could they have done better?

He knows of the threats origin when he says that though, the threats origin is stood right in front of him, he was literally just talking to the threats origin before he says it.

At that point, he knows what they were facing, and he knows what they could have done, and his assessment of their chances is not good.