Coping mechanisms aren’t inherently healthy (meaning: just because you use something to cope doesn’t meant that that thing is good for you or that just because it’s helping you in the moment means it will help you in the long term) and it’s 100% good to acknowledge this. That being said, however, you need to also acknowledge that not everyone is the same, that not everyone has the same experiences or needs or triggers, and that not everyone is going to experience the same coping mechanism the same way.
One example of this is fiction. Using fiction as a coping mechanism (reading or writing) is not inherently healthy. It is also not inherently unhealthy. Some people write and read certain things to cope and it’s an entirely positive experience for them with no drawbacks whatsoever; other people write and read certain things to cope and it’s a bad experience, it retraumatizes them, it triggers them, and it’s more a form of self-harm than it is a way to cope. A person who has a positive experience with using fiction as a coping mechanism cannot assume that everyone will have that positive experience just as a person who has a negative experience with using fiction as a coping mechanism cannot assume that everyone will have that negative experience.
This same thing can be said for pretty much any other coping mechanism—drawing, listening to music, knitting, exercise, taxidermy, cooking, whatever. All of them can be healthy or unhealthy depending on the person who is using them because not all people have the same experiences in life or with different ways to cope. A coping mechanism that is a saving grace for one person can be total hell for another and both these experience are valid, one does not trump the other and they do not cancel one another out.
So when it comes to mental illness, neurodivergence, abuse, and trauma, the fact remains that the individual knows their own experience more than you do and when it comes to what they do to cope if that thing is not harming other people and they say that it is a positive coping mechanism for them, it is not your place to tell them they are wrong and need to stop particularly when the only evidence you have that they are wrong is your own experience with that coping mechanism or your own personal bias about it (facts, science, evidence make for good arguments; personal anecdotes such as “this was a bad way to cope for me so it CAN’T be a good way to cope for anyone else” and emotional pleas like “this thing personally squicks me out so it must be bad” do not).
Now, if you have concerns about how a person is coping then by all means (politely) talk to them about it! But if they say that what they’re doing to cope is positive for them, if it is not hurting them, and if it is not hurting anyone else, then you seriously have zero place to then start talking over them and acting like you know their own mind better than they do and you certainly have no place to attack them over it, either.
Mental illness, neurodivergence, abuse, and trauma are not black/white issues. They have nuance and the people who experience them are not all the same. When discussing these things and reading what other people are saying it is absolutely imperative that you understand that your experiences are not everyone elses, that you do not always know what is best for other people more than they do, and that if you’re talking so much and so loudly that you’ve found yourself incapable of listening to anyone who isn’t talking in unison with you that you are missing out on most of the discussion.