If you define back story as "We have to go through here before we can get to this place".
I'm mean honestly, FFX's plot can be described as 50 hours of "Are we there yet?" Also, the area's were only explained cause Tidus had never been to these places; in FFXII, your party is more informed about their world, so it would be stupid to have a damn cutscene every time you enter a new area just so you could have Basch or Fran explain that this is such and such place. In that context, it would be poor writing to have it explained in a cutscene. The Beastery guide was a better choice, cause it allowed you to not break the illusion of the world.
Also, what monsters are explained in FFX? Outside of Sin and the Aeons, I don't remember any boss having some unique or interesting moment that completely defined their very purpose for being there.
I understand that you don't care for the game and I'm fine with that, so let's just leave it at that.