Sure, suicide is easier with guns, but Japan demonstrates quite well that they are hardly a prerequisite. Guns are banned in Japan and so, to the other commenter’s point, they find another way to achieve their goals. Guns aren’t even statistically the most effective, drinking on train tracks is (or doing fentanyl on the train tracks, hit ya with the 2x.)
You can all keep insisting that the attackers will switch to the next best thing but if that was the case, every other country in the world would have an equal amount of murder sprees, just committed by cars instead?
Sure if you don’t account for any other differences between countries like mental health or other social services, or culture, or anything. Unfortunately in reality it is rarely that black and white, there are other differences.