And you should talk to cops about the effectiveness of attackers with blades against a trained officer with a holstered weapon closer than 21 feet. But both those and the pepper spray/taser fails are outliers, they are not the norm.

In a last resort, I don't want my attacker using my weapon against me, and if they can, I don't want it to be fatal. Which is why I don't carry knives for self defense, even though i'm trained in eskrima.