In my case I've never wished for something as undesirable as existence, even when I was very young I found so much comfort in the thought of eternally ceasing to exist, no matter what I'll always prefer the sound of the true peace of non-existence to suffering in this futile and cruel existence.
I've never tried to end my own existence properly because of lack of access to reliable methods and I'd fear trying to die going wrong and leading to way worse suffering, it's horrifying to think of that happening. And I'm not ill for preferring to not exist, so I don't understand what the "better" part refers to as existence itself is the true problem. In my case suicide is rational to find peace from the futile and torturous burden of existing as a human, I have no interest in suffering and in existence there is endless potential to suffer.