People are bad at removing friends and family that contribute to their poor mental health.
If you talk about real life, a "hack" that I also discovered by myself is called "grey rock method" -- for people you cannot cut out of your luck, you respond in such a generic, brief, unemotional way that there's no payoff for them in interacting/playing with you.
You might be interested to know that you can actually deactivate your Facebook account while still retaining an active Messenger account if the ability to message is all that's keeping you around.