I'm against anything that prevents honest discourse or over-protects people from learning experiences.

That said, it's easy to see that if you have had a traumatic incident in your past, you may want to avoid things that make you think about it. Rape is a particularly visceral example - the memories are in the back of your head, and you try to not think about them, but they can be brought up because of conversational topics, news articles, etc.

Ideally one is psychologically strong enough that this is just a moment of pain before moving on; but for some people it's clearly not so minimal. Being empathetic, I can see that it would be nice to enable these people to get through most days without having to re-experience this sort of thing.

I can't see how a trigger warning would accomplish this. Putting "TRIGGER WARNING: RAPE" at the top of an article is just as likely to serve as the trigger itself. Even just putting "TRIGGER WARNING" on its own will eventually do that, through association. If anything, one is more likely to have the memories brought up more often when this kind of headline / disclaimer abounds.

What i meant was that even if you like the concept oftrigger warning, surely you wouldn’t think that they will make reading the content less painful? I always assumed that the idea is that people should be able to avoid reading it altogether, I can’t see how it could possibly help reading the works “Trigger warning: rape” before reading about a rape, it would still remind you of the traumatic experience.

Yeah, that's basically my point. The only way it could possibly work is if you had some client-side thing to filter out anything with the warning so you didn't see it at all.