I see we are talking about two difference things.
Suicide may be a rational option for people who want out of this life, yes. But actually committing suicide is not just a result of a rational decision, at least not most of the times.
Essentially, what i'm arguing against is not the rationale some people have for wanting to die but the "courage" part. Some people may be able to defeat their fear of death, like the general who ate poison in the video i posted did (and you can still see his hand tremble as he did it, where as i've seen videos of people who killed themselves with absolute calm), but my argument is that in a lot of cases people who manage to kill themselves are able to do so not because of their courage but because their minds are either in a state of psychosis or a schizophrenic one where the "act" isn't actually fully real to them.
This is why many incels can't commit suicide, even though there's very few things in life that can cause as much suffering as inceldom does. I mean sure, you can say most incels are cowards but if your argument is that suicide is invariably always the result of a rational decision taken because of suffering, it's still odd that suicide isn't more ubiquitous among a group of people whose suffering exceeds that of almost everyone else. Something else is at work that allows one to overcome the "fear" of death.