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

[Jagick]

Answer me this, because I'm growing more unsure and disappointed by the moment. That trial battle with "Zodiark" which wasn't even Zodiark but Fandaniel basically possessing him while he was still sundered and unfinished. Is that really it? Was that the only engagement with Zodiark we get? A fight that isn't even really Zodiark? It was the most underwhelming reveal of this ancient all powerful primal god I have ever seen in any story medium ever. Was that REALLY it? The end of the Zodiark arc? The main villain is really just some last minute Mass Effect 3 tier "Starchild" BS?

Furthermore, was Zodiark seriously only being contained by some shield that can apparently be taken down by anyone with enough aether to throw at it? By some technological weapon even the Garleans could have devised? Hell, at this point I think THAT would have been a better story. The Garleans discover this ancient primal god contained on the moon and in an attempt to destroy it, accidentally set Zodiark free thus beginning the final days or something like that.