Honestly what I feel like they should do is Create a system where random monsters can drop treasure chest, or be stolen from to get secret items. Turn the open world into something fun that can lead some where, a few ways is the transportion of airships,boat travel should have random encounters. Perhaps allow us to spend time in the open world for unlocking new partners to replace the chocobo. If we want to grind for lets say a wyvern to be our partner we go to x and grind to prove our worth, or gain an egg. That we then have to hatch and raise into a partner. Throw in dungeons in the open world that can give more exp than the ones people que for, and can be done with large groups that can random spawn unique monster that can drop special crystals that can be used to empower an item. For example lets say we want poison attack we grind poison sharps that can be melted down and placed on our weapon to poison,blind etc this could be fun honestly to add items in the open world we can grind parts for and put on any gear we wish.