I'm surprised this hasnt been mentioned yet. Allow me to present you with a potentially useful site:
https://www.doesthedogdie.com/
Basically, it allows you to search up a given movie/whatever, and see if certain triggers are in said movie, without getting the whole bloody thing spoiled. So you can go "okay, is there any scenes of abuse in here", scroll down to that, and be like "okay, nope, that isnt in this movie". This is of course assuming that the movie in question was properly entered into the database.
Now something seems to have gone horribly wrong with the site's formatting since I last was there, or my browser has gone insane, but it's useful for anyone who finds that they can get a bit traumatized in any way by certain types of content.
Now in my case personally? Dogs/cats getting hurt or killed is the main thing that'll set me off. Dont even bother trying to get me to watch something where THAT happens. No, I wont "power through it", but I will likely go after whoever put me through it afterwards.
Beyond that... gore overload. I can handle some gore... I'm a horror fan, of course I can see some blood and such... but there's certain times when something takes it a bit too far, or does it in such a way that just seems too realistic.
Though this can seriously be all over the place for me. Like, someone getting a finger cut off slowly and it's all extremely realistic and such? ugh. UGH. No, just no. Someone's head just freaking bursting or splattering and bloody bits flying all over the place? LOL.
Look, I never said it made any sense, that's just how I am with that. I will say though, I overall prefer my horror stuff without blood/gore. I'm more a fan of things like cosmic horror and things that go with that type of theme, rather than slasher horror (which can be kinda dull, honestly)
I do think some things should be labelled/rated/whatever beyond just movies though. Youtube in particular could use some on certain things. There's one series in particular that stands out to me, a series called "Dont Hug Me, I'm Scared". If you were to see it, it LOOKS like a show for kids. Everything's fuzzy and there's Muppet-like characters and whatnot. Many clips and screenshots will be just fine. There's singing and everything. But then you get to certain scenes, and... yeah. I adore the series, absolutely freaking love it, but kids seeing it while expecting happy fuzzy fun are going to have nightmares for the next decade. There's no warnings on it though, no indication that it has those elements until they pop up, and they pop up *very* abruptly. Particularly in episode 5 of the original web series. Even I was a bit bothered by... that. For your sakes I wont describe what "that" was.
I will say this though, for any parents: For the love of puppies, check out things your kids are going to watch BEFORE you let them watch those things. Sometimes a show or whatever isnt what it first appears to be.