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

[MikkoAkure]

Yes, it's true. The Reaper job quests go a little deeper into it as do some of the side quests in Garlemald itself.

The Garleans were simply peaceful farmers who settled in Corvos and worked the land yet due to it being rare for them to be able to manipulate aether, they were targeted by their magic wielding neighbours.

Bit by bit, they lost their land. It didn't happen quickly and occurred over a period of roughly eight hundred years. This is why it isn't as simple as 'getting over it' - and then even when they were forced into the bitter frozen wasteland to the north they were still under attack there as well.

It was only when Emet-Selch stepped in that their fortunes reversed - albeit briefly.

G'raha's people held the land thousands of years ago during the time of the Allagans so I don't think it's as simple as that. Fourchenault even says as much:

Those unfamiliar with history would believe they have always resided in the bitter cold climes of northern Ilsabard, but that was only after the Corvosi invaded eight hundred years prior.

With the advent of magitek, I imagine it was all too easy for Emperor Solus to rally his people and take back what they believed to be rightfully theirs.

Yet history would tell us true─that the land they call Locus Amoenus has been known by other names, and served as home to myriad peoples.

Indeed, one need only look back to the Allagans' reign in the Third Astral Era to give the lie to Garlean claims of sovereignty.

Yet even had they such ancestral ties to Locus Amoenus, antecedence cannot justify their animosity to foreign peoples.

Animosity poorly veiled by delusions of justice, as has been the case for so many nations throughout history. Would that man had the sense and strength of will to break free from such chains of hatred.