I wonder why breath is the only aspect that is partially tied to what we consider 'a usual elemental power'

Well, I mean the Betas are sort of associated to the 4 Classic Elements, so it’s possible Hussie also intended the others to be associated to their Elements to begin with, before the Trolls and adding another 8 Aspects on the mix happened. That being said, with its ties to Freedom, “Room to Breathe” “A Breath of Fresh Air”, “Free Like the Wind”, it mostly seems to stem from wordplay, so the Aspect regarding Freedom would of course be tied to Wind.