One question, does a few seconds of text prevent you from seeing a film? Sure, people who don't like whatever it is would save their money and skip the whole thing. But what would you gain for forcing them to see part of the film and the scene they want to avoid because the film surprises them with it?
Why exactly triggers bother you more than disclaimers, that are also a few seconds of text offering information?
I think that the real answer to this is "because they won't support things that you like but they dislike anymore" and if the things you like doesn't have enough audience it could be cancelled. But that is life, i can't force people to see the expanse even if it is a great show. You shouldn't force people to see things that hurt them or that they dislike by surprising them with it.
By the same logic, let's get rid of meta critic, since it prevents you from seeing terrible films. It is better if people can't comment and you can "just walk away" (after paying and wasting your time) if it is terrible!
Triggers are just that, a warning. They see the trigger, identify the film as something they don't like and walk away. You stay. The end.