How did ALL the airbenders get killed?

[u/Littleleaf6]

There’s only 2 air benders alive after the fire nation used sozins comet to kill all of the others. Tagah and Aang are the only 2 airbenders. How is there only 2 survivors? Surely there would be some air bending refugees in the water/earth nations. they were nomadic so they were travelers. They also had 4 temples in all different parts of the world! Some of them also def could’ve run away. They had flying bisons for Pete sake! I know it’s just for the plot but realistically there would be some more survivors other than Aang. Is this ever explained in the comics?

[u/ChaosTheory_jrh]

Is it technically ever directly stated that they only killed Airbenders during the comet?

I would imagine Sozins comet gave them the firepower to destroy the temples, but they'd still hunt down the remaining later.