I was thinking about this recently myself because it has been a difficult aspect of my "post-therapy" life. I have since remarried to a caring man, and I have friends, and I have learned to navigate relationships in much healthier ways. In those areas, therapy has been very helpful and successful. But because the therapy relationship cannot be replicated in real life, the emotional safety inherent to the one-sided, parent-child sort of relationship I had with my therapist simply does not exist in my life anymore. I miss that sense of safety, where I could tell this person anything, knowing he would do his best to understand and accept me without judging me. It was the first time in my life that I had ever experienced this kind of emotional safety, so even though my therapist was far from being a "reparenting" therapist, the relationship itself met some of those unmet childhood needs.
I know my husband loves me, and he meets many needs that could never be met by my therapist due to the time constraints and the boundaries of the therapeutic relationship. I know that I have a more fulfilling relationship overall with my husband than I could ever have with a therapist. I don't have a problem accepting the give and take aspect of "real life" relationships and I don't expect my husband to give of himself unconditionally. But he will never be able to meet that one need my therapist met -- the childhood need for unconditional emotional safety.
I will probably always miss that part of our therapeutic relationship. But I have found that I can almost, but not quite, feel it in my memories of interactions with my therapist. It's not the same as actually being there, but it's close enough to give me some comfort when I need it. I might not feel the actual safety anymore, but I can feel the calming warmth and comfort it brought me when my therapist met that need in our relationship. Yes, it's bittersweet and at times I miss him terribly, but I am glad I have the memories and the feelings they evoke in me when I need them.