Your brilliant battle plan sets up a turn 5 win via controlling more objectives or having more kill points. Only for the dice to disagree and the game keeps going. Your opponent cleans off objectives or at minimum contests them/or gets some kill points. Then you claim them again on turn 6, only for the game to
fo to turn 7.

Now you have little forces left and settle for the draw, if not getting beat.
I can count on my second set of fingers how many times this has happened to me. Let's hear what went wrong with your games or how you plan for such unknown debacles aka "dice saying play on"