Right but several types of therapy stress authenticity and genuineness. Some self-disclosure can be used to establish the therapist's humanness. It prevents out of bounds projections if the client knows that the therapist is neither all powerful or their parent. Therapists who are honest and reveal certain limitations and/or vulnerabilities can actually help ground the relationship in a more realistic sense of things. Thus, unrealistic expectations, boundary violations, snooping or obsessing can be curtailed by the therapist providing some sense of themselves. I think it develops kinda naturally over time anyway. It also fosters trust for those who have trouble with that. But I agree, as I have already said, the mistake is to believe it is a reciprocal relationship. It is not and can never be. And that's a good thing.