I don't think you understand the point of suicide.
It is to end your life earlier, not when you're already dying. Suicide can be the optimal choice in a life anyway, a life of torture or a long life of torture. Your choice.
And a lot of the time, it isn't because of teen angst but because of poor living conditions. Regardless, you shouldn't be telling people what they do with their life. If someone told me they wanted to kill themself I'd hand them a gun and tell them to do what they want, even if I disagreed. Because I'm in no position to say what they can and can't do.