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

[KageTokage]

Since for some reason the antagonists always need to be ascians or garleans.

The Garleans have long been the only significant source of strife on the Three Great Continents outside of civil wars like those in pre-occupation Ala Mhigo, so unless there's some closet military power hiding in Ilsabard and waiting to make their presence known, I have trouble thinking of who/what else could realistically serve as the antagonist for an Ilsbard expansion barring the introduction of some new supernatural threat as a consequence of Endwalker's events changing the natural order.