Dear OP:

Have you maxed out every class? Maxed out your botany, mining and fishing? Completed every quest in the game? Acquired all the mounts, pets and Triple Triad cards? Have you been checking off achievements one after the other? Gotten everything there is to get with hunt marks? Maxed out your squads? Gotten a set of end game gear for every class you've gotten to max? What I mean to say is that there is plenty of content to work on and things to do. If all you care about is level 80 dungeons and raids then that's a you problem, not a content problem. There's lots of end game crafting to be done that is extremely profitable, such as running level 80 maps for the indigo cloth for the Summer Indigo shirt. (The cloth alone sells for 2 million a pop, let alone the top itself is sitting at right about 5-8 million gil.)

Anyroad, there's lots of things to do. Not all of it has 'level 80' stamped onto it but there's LOTS for you to still accomplish and my bets are on that you haven't.