FFX has in common with FF6 and FF7 (but very much not FF8, FF9, or FF13) a storyline actually written with some basic command of narrative vocabulary: it has characters who each serve a purpose within the story (and whose interactions with one another are grounded in a plausible shared history); it has a story built on actual rhythmic beats, with a natural three-act structure and a traditional climax, without any shaggy-dog meandering nonsense; its plot is built around a coherent set of narrative themes, which are established upfront and then continuously explored throughout the story. I honestly think all of that is much more relevant than the sort of "LOL tidus is whiny!!!" critique people sometimes toss at it.
It's certainly true that the game is full of incomprehensible hippy-dippy nonsense, but, like, that's Final Fantasy, dog.