It amazes me when people forget this is a common courtesy. Also, if you like following someone in particular and they post things that trigger you, you can sometimes find ways to creatively block things they don’t tag for and continue to enjoy their other posts.
For example, Seanan posts a lot of frogs. Pics and vids of frogs squick me, and are related to some personal triggers, so if I’m already having a bad mental health moment seeing those can make it much worse. I love everything else she posts about and would be sad if I had to unfollow her just for the frogs. So instead, I have the name of the blog she usually reblogs frogs from as a blacklisted tag on xkit, and that knocks my chances of seeing frogs on her blog down to like, 5%. Doing that keeps my dash a safe space for me to relax and have fun, without asking her to second guess posting the things she relaxes and has fun with.
Sometimes you need to unfollow people, for the sake of your health in internet usage. And sometimes there’s workarounds you can put in place yourself to tailor what you see of someone else’s blog. But putting all the work of protecting yourself on the internet into someone else’s hands is unfair, to them and to you.