Garlemald's broader issue, like many empires introduced in the Final Fantasy franchise as a whole, was that it merely ended up being a front for something bigger. The instant that the latter part of Stormblood revealed that Varis was no more than a puppet dictator under Emet's thumb with no meaningful power of his own, Garlemald itself was devitalized of its story potential. What's the significance of going head to head against the Emperor in a climactic battle when we've already crushed the Ascians? He couldn't even be considered as a Mid-boss. Where is the mystique in exploring the modern city of Garlemald when Amaurot is even more modern in appearance?

There was no opportunity to make Garlemald more interesting without wrapping up the Amaurotines' involvement in the story, preferably for good.