I will preface by acknowledging that we haven't heard anything about racial augments in a long time, and that Steven has expressed a desire for your race choice to not be motivated by gameplay effects. This sort of suggests that racial augments are a thing of the past. But I like the idea of them, with a caveat.
Racial augments, in my opinion, would provide an interesting bit of flavor to your race choice, but I agree that racial abilities in their traditional implementation coupled with min/max culture tends to funnel players into picking the race with the "best" racial(s).
Vanilla WoW had this problem especially with its priest class, where specifically a dwarf priest was pretty unambiguously the best healer priest choice because they were to only ones to get access to the fear ward ability, something very very useful in certain encounters. But with WoW Classic's Season of Discovery, priest racials are still learnable by the race that they belong to, but with the addition that the ones from different races are available via quests from their respective races. The quests themselves are underwhelming, boiling down to "go talk to this guy" to learn the ability, but I think the idea is solid.
So here's my proposal for Ashes:
Each race has unique augments unlocked at some point by default by members of that race, for example maybe Py'rai get a level 10 augment that can be applied to CC abilities called "Constricting Vines," causing vines to grasp the target's feet, adding a 0.5 second root to the ability effect. Py'rai would gain this augment automatically at level 10, but all the other races would need to complete a quest in order to unlock it. This quest line would be available from Py'rai nodes of a certain level, and would be an exploration of Py'rai culture. Maybe the player would need to complete a certain hunt, or perform some kind of rite, culminating in the player unlocking that augment for use.
Under this system, it would probably be better to call them "Cultural Augments" than "Racial Augments."
I'm not a fan of the idea of backgrounds, either. If they provide some mechanical benefit, there will inevitably be some "best" choice for archetype x. I think it's bad design to lock players into a choice they were forced to make when they didn't understand the game.What would make you like the background system more? Perhaps besides simply less of a mechanical importance? Also, awesome thought-starter in your OP <3