It’s harder to kill someone with a knife than a gun and it’s even harder to kill lots of people with a knife than a gun. This should be extremely obvious, but since it’s not, learn something new every day!
Well the event I’m still addressing concerns 2 people killed, not lots. In general it’s easier to kill someone with a gun, but it is easy with a knife too. The differing amount of effort is no consolation to a dead person.
When the increased time, effort, and struggle means the attempt failed on one of the intended victims, it may not console the victim (assuming there is one), but as I said earlier, the survivor may think differently.