I think it depends. Personally, for me it is at the moment, because sometimes I want out but feel like I can´t start seeing another therapist. I think this is both due to my therapist´s style and (especially) part of the issues that brought me to therapy in the first place (becoming very attached to unavailable people or people who hurt me). I know people who also feel addicted in one way or another and others who do not. I know therapists who respect clients' autonomy and others who, unfortunately, not so much. I think the good, ethical, informed therapist needs to be highly aware about individual differences around this issue so that clients are empowered and don't end up feeling trapped.