Slayer, the mode that comes down to getting the most kills, could theoretically fly—there are fewer people on your team for the enemy to kill, meaning that it will be hard for them to score.
But for the most part, an unfilled ranked match is completely depressing and demoralizing.Things actually count in this mode, after all, and the game tries to place you in an ecosystem full of people of your approximate skill level.
What’s worse is that there’s no actual way there aren’t enough people to fill those slots.