It warms my heart to see you deep dive into this game's story, in spite of its popularity I feel like not enough people really do that.

I suppose your analysis is primarily aimed towards the world of Spira in itself, which is fair but one thing I'd like to bring up is that while it's memed a lot, this game is not Yuna's story, but Tidus'. It's not a story of merely Spira itself, but rather the story of an outsider to all this coming to learn of this world, all of its suffering, how people cope, how people despair, how they try to live despite it all, clinging to faith or their friends. Tidus is an outsider to Spira not just physically, but also in spirit - in Dream Zanarkand, it's a "rarity" and "big deal" for a fiend to show up. And as Wakka puts it on the S.S. Liki: "Hating your own father. Sounds like a luxury to me. I don't even remember my parents."

Tidus is a boy with first world issues thrown into the third world and being hit hard in the face by its reality. He follows in his father's footsteps more than he'd like, both deciding that the most meaningful thing they can do with their lives is to use it for Spira. And they both do it with a smile and, at the very end, high five each other, no regrets over the path they chose.