Its a fantasy.
With my sister, she ended up in rehab. So we were all there for family week - a week of intense “family” therapy. I won’t say it was useless - but in some ways the therapy hurt the family relationship (but we weren’t estranged) worse than no therapy would have. She had to want to change - she wasn’t ready to change - therefore therapy wasn’t helpful. And in rehab, family therapy turned out to be a great way for the addicts to blame their families for their problems - I wasn’t supported or validated enough so I drank.
But if you don’t want to actually move to a breach, if you haven’t tried setting limits and the “ignore feature” on a relationship - sometimes that can be successful. We had that relationship with my grandmother. We’d pay lip service to having a relationship with her, but I don’t think I saw her more than twice a year in the ten years before she died. A lot of times a breach happens because every encounter is difficult and the quantity of encounters is overwhelming. If you can keep the encounters to a minimum, and keep your boundaries intact during them - sometimes the relationship survives. It isn’t a HEALTHY relationship. It doesn’t satisfy your desire for “a mother who always loved and supported you.” But it can keep some of the guilt away.