For being the season of "revealing all", they revealed nothing other than solving the storyline they just created that season. All of the good questions went unanswered.
This is true things remaining unclear
Is the smoke monster actually dead?
Why do all of the spirits of everyone who dies on the island seem to stay around?
What was the smoke monster and the light and the wheel?
How come the rules of who could hurt or kill who only worked sometimes?
How did Jacobs foster mom get on the island?
And many many more