Many objects are meant to kill by design. Daggers are frankly entirely useless as a knife except stabbing people but would you sue a company for making one? Even then if daggers were banned people would just use kitchen knives.
The bullet that kills the most people in the US is actually the scrappy little .22 LR, a very weak cartridge. If all guns were banned a knife or a variety of other things isn’t much less lethal.