User blog comment:IamJakuhoRaikoben/Chapter 439: Albareth Empire, Review./@comment-5303512-20150608065717/@comment-7418318-20150608082705

I think the very reason the story moves on to another continent is so that the protagonists have someone rouhly equal in power to fight.

Right now there's no challenge left for them within Fiore, except for Acnologia and Zeref, which are probably kept on the backburner for the final arc, and the Wizard Saints, which aren't enemies as far as we know. Everyone else would just be rofl-stommped, so the story moves on to another place with stronger potential opponents.