I been playing since beta ARR in 2013, never been away from the game for longer then 2 weeks since then.
For me personally it's the best game ever, but over the past couple years I've noticed it's better to play other games as well.
As far as burn out goes I just play through it cause I know right now there isn't a game that can take 14's spot as my dominant game.
Dragons Dogma and The Last of Us multiplayer came close but by the time I started those games then Thier content cycles were done, but still those 2 in all Thier glory wasn't as grand as FFXIV in all it's glory.