There was a point (no pun intended) in the 90’s where this was the case. Sharpened and worn under a tubi-grip bandage for concealment. It’s not the case anymore though.Don´t remember where I read (might have been a comment in Matts video) that one of the preferred weapons for criminals are sharpened bicycle spokes.
Any knife can do harm, but it’s about an image popular with gangs.
I’ve handed a few “zombie” knives. Poor steel, no edge alignment, weak handles (para wrap). But they look the part.