You live on borrowed time anyway, death will come regardless. Life is still an experience, I don't think its worth throwing it away if you still got a functional body to go with it. There are plenty of copes worth trying out before you decide to call it quits.
But even then...
Killing yourself is not so simple, most suicide attempts fail. It's ironic, but most hikkimori lifestyle enjoyers go on to live long and lonely lives, very rarely do they commit suicide, well at least not in the early stages of their lives, perhaps that changes for 30/40+. I'm going to make an unsubstantiated guess that there is less suicides in incel circles than there are in the general population sample, in young-adults at least.
That's because most suicide occur as a result of trauma, or prolonged suffering caused by traumatic events. Incel life is a slow death, it's like a vaccine to sadness, you simply learn to accept it as you grow with it because you got no choice. It becomes harder to set your mindset to suicide after that.