An equally arbitrary frame is "the world and life are wonderful".
The reason you may believe one instead of the other is not because one is more fundamentally true than the other, but because of a stochastic process that changed your mind state to one of those.
Once you accept that both states of mind are arbitrary and not a revealed truth, you can give yourself permission to try to change your thinking to the good framing.
And you can find the moral impetus to prevent suicide.
In the pits of depression that first framing can seem like the absolute truth and it's only when it subsides do people see it as a distortion of their thoughts.
Of course, only thereby, through being quite as superior to all others and their thought processes as me [pauses to sniff fart] can one truly find the moral impetus to prevent suicide.