Worth looking into.
Why is it so difficult? Well, as intuitive as it is you still can't really change characters mid-battle as you can with it's predecessors. You have to seriously struggle through the final boss battle (more than any other FF game I've played) (which I won't explain here, I'm not a spoiler writer).
Most of all, items have to be EQUIPPED to use, so if you don't have your menu set to use items, then you depend on magic, GF, etc. (I'm an item abuser in FF games, so shoot me.)
Overall, rather than being one of the most challenging games ever played, it's worth looking into. Just be ready to put serious time into training every party member to about Lvl. 100.