The fact that politics were touched on (albeit very lightly) in FFX-2's story appealed to me. There is still a small amount of political turmoil in Spira because everyone's free to believe what they want but they need some guidance. You have two factions at each other's throats, and one neutral faction stuck in the middle. There's a dichotomy between the two leading factions in terms of age (and age was shoved into the player's face, imo), religion/ideology, solutions to various issues, position towards discouraged technologies and emerging technologies, etc. FFX-2 clearly demonstrated these differences in an adequate way, particularly if you did most of the sidequests and if you did a few playthroughs and took different sides. Even the reluctance that some people exhibit towards embracing Machina was dealt with nicely --though I don't remember if New Yevonites' reluctance of accepting the Al Bhed race was explored as well.
Even if it didn't go as in-depth as I wanted it to, I appreciated that FFX-2 was consistent with FFX's ending in a worldview kind of way--after a certain way of living has been abolished or rendered obsolete, some people still want guidance and a set path to deal with things. FFX's ending left a political and spiritual void, so the factions were created to help guide people. Even 2 years after FFX's ending, you can see that some people are still struggling to deal with the consequences (good and "bad") of the Eternal Calm. And really, I didn't even mind the more lighthearted tone of the main story. I thought it was pretty refreshing in a sense.
When you think about it, Spira's worldbuilding was very well-done in FFX and FFX-2. You know pretty much everything about it because the game made you engage with the world and its people. Even the sidequests in FFX-2 expanded on Spira a little bit.
...And FFX-2 is pretty damn fun to play, but that was sort of a given.
