It's the most dogmatic modality imaginable, operating under the cult of scientism, where the "rational" cognitive behavioral therapist seeks to correct the "irrational" patient (who is considered irrational simply for being depressed/anxious in the first place and expressing these sentiments in words; the therapist's rationality deriving merely from their credentials).
Every experience and impression you share with a CBT therapist is subject to critical analysis as if you're totally wrong in your interpretation of them -- assuming that they are "negative" in nature and lend themselves to unhappy thoughts, or wrongthink (literally called "wrong thoughts" in the therapy). Who knew that "positivity," and associated concepts like "loving yourself," were precepts proven by science?
If CBT doesn't work for you, a principled therapist would theoretically attempt to change the modality or refer you to somebody else, but these are in short supply and in my experience and those of others whose testimonies I've read online, the therapist will just become malicious in a way befitting for a narcissist. They'll attempt to utterly confuse you in the hope of breaking down your ability to think for yourself. In a word, gaslight you. Just so they can continue to justify getting paid $100 an hour under the pretense of changing your "wrong thoughts."
But what actually happens, if any change occurs at all, is not that your
thoughts change, but that your
language changes. You seek to appease the abusive therapist by telling them what they want to hear. This does not entail any improvement except in the context of the therapist's notes and correspondence with the insurance company -- the only thing that matters in the end.