Is This Really a Spoiler? Just in Case: SPOILER WARNING!

On the Internet, there's a lot of sites that publish movie and TV show reviews that often have a giant disclaimer "SPOILER WARNING!" as a way for the reader to stop reading if they don't want to know what happens in the movie or the TV show.

I'm wondering when a spoiler warning is really warranted. Case in point, I watch the show "This is Us" on NBC on Tuesday nights. The previous episodes have made it clear that a major character is dead - we've seen the aftermath of his death played out in the living characters on the show.

Thus, I came to this article - with a major spoiler in the title and wondered what the parameters are for issuing a spoiler warning? Is it assumed that if I click on the articles title, I already have watched the previous episodes and know that the major character is dead?

What about for every single article about TV shows that are done? In this era of binge watching TV shows on services like Netflix, does every article about "Lost" or "Prison Break" need a spoiler warning? What if I come across a TV review that was originally published the day after a major event on either of those shows? If I am binge watching, and haven't made it up to the episode being reviewed....

It'd suck to be the one to ruin a show for someone else. I've read spoilers about movies before I see them in the past because I want to know what to look for in the movie. I knew, for example that HS died in a recent Star Wars film, before I saw it. I wanted to watch for nuances that the director inserted as it progressed to that scene. Perhaps the line in the sand can be drawn between movies based upon actual events are exempt from needing to have a spoiler warning whereas movies that are fictional do. For example, articles that were published when the "Titanic" movie was released didn't include a spoiler warning about the ship's status at the end of the movie, right? But if I go to "Black Panther" next month and don't want to know the plot or how it ends (though seeing the character in the trailer for "Avengers: Infinity War" tells me that the character survives whatever dangerous situation he encounters in the movie), then I should be able to shut down my news feeds and walk in 'cold' and without prior knowledge.