I think it's irrational to actually want to deteriorate from old age, the thought of such a thing repulses me and sounds so torturous. And of course this is a reason as to why I think it's always preferable to cease existing as in death there are no problems and suffering, it sounds completely ideal being unaware of this hellish reality as all that is inevitable for us is to be tormented by old age, we are destined for nothing but to decay, suffer in the process and die anyway.
It truly is so horrible the amount of suffering in this world, the reality is that existing is just a process of slowly dying, we are only waiting around to die where everything will eventually be forgotten about so I could never see any benefit to all this meaningless and unnecessary suffering, the problem is that the human life expectancy is too long, I bet many of those anti-suicide people will change their views when they end up being tortured by health problems as a result of age.
I find it disgusting being trapped in this flesh prison that is destined to deteriorate as to exist means to be a slave to suffering and death is the only escape from this hell. I could never understand why anyone would actually want to get old, I just think the inevitability of old age is why wanting suicide is perfectly logical.