so, a big dragon Deathwing just flies around and causes a cataclysm big enough to change our entire world, but getting pierced by a gigantic sword used by one of the greatest forces in the universe does… nothing?
What deathwing did was like getting doused with napalm.
What Sargeras did was to… uh… stab you once. In a quick hurried manner just before being pulled away. You got stabbed and you are bleeding and its bad, but dealing with that is what bfa is all about.
Had Sargeras had time, he could have probably cleaved planet in half, but he only had the chance to stab once.
Also the true reason first aid was moved to tailoring; if everyone had first aid we’d simply bandage the wound, not enough tailors around to do that now.