[harshreality]

That is a poorly specified, unrealistic thought experiment with lots of hidden variables.

Everything hinges on who attacks first. The weapon is secondary.

Knives are extremely dangerous and more difficult for your assailant to control at close range, and it doesn't seem like you have an appreciation of that.

If you have a gun and if you decide to attack first, maybe you can shoot two or three of them, disabling them, before they can kill you. I've never been in combat, but I don't think that kind of scenario is likely to happen in the real world. Also, even fatal shots are not immediately disabling unless they're to the CNS. Slashes across the arms can readily disable someone in a way that shooting them, even in the chest, won't, unless you hit their spine or some critical nerve or muscle area.

Guns are vastly superior if you have the advantage of distance. Otherwise, not so much.