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

[KizuyaKatogami]

It is confirmed canon that the Allagans created the Ixal, at least! Meanwhile, the Sahagin are apparently Echo-capable, so ???????

EDIT: Thinking about this further (for some reason), I think it's safe to say that at least generally, races/tribes that exist across the Shards are probably Sundered Ancients. Ones that are unique to a Shard, such as how the First had no Ixal, or the Source has no Amaro, probably have different origins, such as being familiars. Namazu were confirmed as existing in the First before the Flood, though, which would mean that it is likely that at least a few of the Elpis NPCs did, indeed, become delicious sushi.

How do we know they’re sundered ancients and not say, some of the sundered new life that sprouted after Zodiark restored life to the planet?

[Brinne]

How do we know they’re sundered ancients and not say, some of the sundered new life that sprouted after Zodiark restored life to the planet?

That's possible too! That's why I said "at least generally" since, again, the Sahagin are shown able to carry the ability explained as a sign of being a former Ancient soul.

I will certainly also take Emet-Selch being so conflicted over feeding the Namazu to Zodiark he misconstrued that as being the source of the Hydaelyn-Zodiark war. Either way is hilarious.