Let's make it with an example. Imagine that you are without any friends, you move through life coping, you are constantly bullied in school and people hate you for plain existance, despite you doing nothing wrong.

You go to a therapist, you see a therapist who is dude who abused drugs in his youth hard and recovered or a foid, who is mentally sick bipolar schizoid and wanted to learn something about her mental problem and passed university somehow.

You open up and tell about your problems, how lonely you are, how suicidal you are, how you do stuff but you don't see a single reason in doing this shit because it leads nowhere.

They listen to you, but they don't believe you. Instead, they give you bullshit social exercises, which you can do for eternity, but they will change nothing, because you are trying to deal with effects, rather than with the problem itself.

They can't make you less lonely, they can try to make you FEELING less lonely, as your urge to meet people will decrease. They will imply the rules that world obeys, which are so completely false, that you can't even try to believe that anyone respects those shit rules. You will pay money for this shit, leave the therapy and you face the same world as an hour ago.

Nothing has changed. Neither your looks, neither the treatment, neither the people who are terrible.

Therapy is only meant for people, who didn't yet realised how this world works. They are programmed to cope with rejecting any possibility, that the world works differently, than some random FOID has taught them in therapy. They can be given thousands examples, they will feel suicidal, but will always reject this idea. If you know how this shit works, you can't forget it. No matter what.