The magic of illusion is probably world renowned but costly and limited for most. Ul'dahns and the patrons of the Gold Saucer have had to deal with glamoured demons, for example, and there's no reason to believe based on the quest to unlock Glamours that it's all that rare or difficult--just that no one thought to use it in that fashion before.
As for Yugiri, it may have been that an illusion would have been costly or wasteful for a refugee. It may have been impractical too, given how much action she sees and how much time she spends in public (Glamours have been notoriously unreliable in the story).
Personally, given the fact that Au Ra are neither restricted in their presence in Eorzea (the patch notes say that they will be Gold Saucer dancers in a few days), nor is the Warrior of Light restricted from having been one this whole time, I strongly believe that Yugiri was never hiding her face because of her race alone. Rather, between being a political target and the representative of the predominantly Hyuran Doman people, you could imagine that the rarity of her race might set her apart and draw attention or empathy away from the Domans. Yugiri probably did not want to distract the Eorzeans from her people's plight.
It was already bad enough that they were Easterners. I mean, if you doubt how racist and xenophobic common Eorzeans can be, you may want to check out an Eorzean timeline. Or those old in-world news report posts they did in 1.0.
As for Yugiri, it may have been that an illusion would have been costly or wasteful for a refugee. It may have been impractical too, given how much action she sees and how much time she spends in public (Glamours have been notoriously unreliable in the story).
Personally, given the fact that Au Ra are neither restricted in their presence in Eorzea (the patch notes say that they will be Gold Saucer dancers in a few days), nor is the Warrior of Light restricted from having been one this whole time, I strongly believe that Yugiri was never hiding her face because of her race alone. Rather, between being a political target and the representative of the predominantly Hyuran Doman people, you could imagine that the rarity of her race might set her apart and draw attention or empathy away from the Domans. Yugiri probably did not want to distract the Eorzeans from her people's plight.
It was already bad enough that they were Easterners. I mean, if you doubt how racist and xenophobic common Eorzeans can be, you may want to check out an Eorzean timeline. Or those old in-world news report posts they did in 1.0.