As someone who loved it, why I think Dawntrail didn't work for everyone [Spoilers]

[Cleretic]

She learns rituals might have more to them than face value. We never really see a ritual play out later in story where she can surmise "there's gotta be more to this...". It could have been something as dumb as "There's a tea-ceremony ritual most people in Solution 9 do, but this one boy hates tea.... turns out that tea negates the lightning sickness, and that's why they drank it originally."

She learns to overcome her fear with Alpaca. We never really have her face a major fear after that.

She convinces an artisan to live somewhere else; this could have been a moment for her to learn from Alphinaud about persuasion, then later USE that to talk to the red Yok Huy instead of Deus Ex Machina (with Alphinaud nodding in approval).

The only one arguably used is that food can be a bridge between different cultures and warm relations, but I even that was G'raha getting ice cream.

You mention the use of food as a relational bridge, but I don't know why you mention G'raha eating bad ice cream in Asyle Volcane, rather than her literally evoking that around the meal with Otis, which is a scene that gives her more of an idea of Alexandria's history than actually talking to their queen did (a queen that incidentally cannot build that bridge, because she cannot eat). Her entire reasoning for opposing the Alexandrian soul recycling system (and Living Memory by extension) stems from her knowledge of the Blessed Siblings; that just because a practice is really old that doesn't mean it can't be stopped, and that just because it came from a good place doesn't mean it shouldn't be stopped.

There's also her using Zoraal Ja's constant and obvious predilection for 1v1s against him, and the ongoing theme of her asking for the input of the people around her, which grows in how she approaches it; first as a show of her own insecurity with the Hanuhanu and Pelupelu, then as a very intentional method of understanding why the people of Mamook are like that, and finally as finding the tools they need to beat Sphene while not disrespecting the dead she's fighting for within Sphene's kingdom itself.

If you want to say that you wanted to see her use more of the tools she picked up during the rite of succession, then let's properly respect and recognize all the tools that she did use.