This is to some extent unavoidable in an MMO, or at least a story-driven one. They can't ever completely
finish the story because doing so would leave players with no further reason to stick around and keep paying their subscriptions. The "to be continued" type of climax is there because SE needs the game to continue.
They have to keep providing a series of climaxes that are big and impressive enough to excite players while still allowing the followup to turn into buildup toward's the game's
next big climax. Whereas a novel might do this a couple times with intermediate climaxes, then build to a bigger final clamax and denouement, an ongoing game doesn't reach a
final point unless something goes so horribly wrong that they have to get drastic and drop a moon on the whole thing or something. [Dalamud— for when you need a moon-sized reset button. Ok, sorry, somewhat random thought there.]
They should still tidy up any subplots that have run their course, but the lack of a final point in the story prevents the sort of clean denouement that ties up all the loose ends.