It is about preventing needless suffering. So, if suffering constitutes an overwhelming part of life, one should not procreate in order to avoid it. Sure, we may have our coping mechanisms to get around the suffering, but why learn and deploy them when it can be avoided altogether? It is not for the benefit of the child that they are being brought into existence.

This just doesn't track with my lived experience. I have personally had my fair share of pain in life, but not so much that I wish I was never born, or that I want to prematurely die. The suffering is there, but not so much that it is overpowering or unbearable.

Am I enjoying life because I'm deploying coping mechanisms and don't even realize it? Maybe. Is my brain tricking me into thinking everything is fine? Maybe. Does it matter? I really don't think so. The subjective experience is what matters.

I would say overall that I've enjoyed existing and am thankful for it, and I don't know how to square that with the argument you're presenting.

Avoiding all procreation to prevent the possibility of future generations experiencing some level of bearable suffering seems like throwing the baby out with the bathwater.