it doesn't work when the patient is able to
1. Analyze the actual processes that therapists use to diagnose and then treat certain illnesses.
2. When the patient knows the DSM-5 like the back of thier hand.
3. When the pateint can logically see how mental diagnosis work, and how they have been used for centuries to misdiagnosed women and perpetuate misogyny.

Take for instance Borderline Personality disorder, the disorder now heavily mainstreamed to describe the "psychotic ex girlfriend."
Once labeled with this diagnosis, providers treat you as if you have the plague.
Take a look at the symptoms that constitute this diagnosis. All of them relate to responses from truama. The diagnosis and treatment of it actually aims to punish said survivor of truama as inherently wrong in their response to it.
It demonized women. Is connected to the history of conducting hysterectomies and institutionalizing and experimenting on rape victims.
How can psychology or therapy help, when the actual culture of it isnt really scientific at all, but rather operates off of hypothesis which aren't definitively proven?
Therapy doesn't work for everyone.