Well sure, I suppose you could stab someone in a vital spot, I have a few highly decorated ones that have very sharp points which I assume were intended to be worn in a hair bun at the back of a woman’s head.
Come to think of it now, maybe those women aren’t just wearing them for show or even for eating.
Anyway, anything can be used as a weapon if you put your mind to it, even these relatively blunt plastic chopsticks this guy is throwing.
I’m pretty sure the secret is in the velocity he imparts to the stick, that and the fact that the stainless steel pan he’s using for a target is kinda thin. Even so, you notice that the steel hasn’t simply been stretched and split because of the dent, it cut a disk shaped hole and then the metal curled back on itself.
But a human body isn’t stiff metal, it’s more resilient. That said I doubt if these thrown missiles would do much more than cause a minor superficial skin wound. No way they’d penetrate deep enough to be lethal. Still, it’s an impressive trick.