>>713380319
Based on the two shown and one implied instances of airbenders suffocating people, it's actually really hard to pull off without killing yourself. Gyatso killed a whole room full of people but took himself out too, presumably because it's easier to just keep air out of a whole area centered on yourself. Meanwhile in Korra, Zaheer uses precision suffocation twice, and each time only on completely helpless targets because it requires concentration and a constant unbroken motion.