The person who went NC has come back when they have been in trouble and I think they should keep some contact so that it is not so obvious that I need you now and I don't want you now.
or - they went NC for good reasons. But going NC is desperately hard. You want the love of your parents, the help of your parents (as is natural) and you long for that, especially if you haven't internalized security from a young age.
If you do go NC, then when the shit hits the fan sometimes you do go back hoping that this time it will be different, this time the love will be there and support. And when the crises has passed and it's clear that the old patterns are still there, the ones that were so bad that you went NC, .... you slip away again.
If you're lucky, one day you realise that that help will never be there and that you are better off on your own. I mean that literally.
I have never NCed anyone. I would rather talk it out.
You've never had the experience of talking to someone that you cannot possibly ever get through to, have you? either because they are severely mentally ill or because they have already have an agenda that they are not going to listen to you.
I am sad that all kids did not have such a good childhood but I do have things like divorce and associated problems and a difficult birth in my life now as payback probably
there is no payback. There is no evening-out. Some people just have bad luck and have done nothing to deserve it, but have to live with the consequences (and also have to decide not to become self-pitying mushes but actually get on and -live- their lives, as a corollary)
Life isn't easy like checks and balances. Life is random and you can get some good luck and some bad luck. Karma doesn't exist, ime. It's a pretty fairytale to make people feel better because actually, you need luck and your own determination to make a reasonable life. Some people get kicked in the teeth from the very beginning. It makes everything harder - especially when you're faced with the uncomprehending assumption that there's two sides to every story. yes there are, but sometimes one side is not true.
You aren't going to understand, Bouquet
The best thing you can do, if you really want to help, is to stop expecting everything will be okay, stop judging, and offer to be there for that person if they want to ask help. And to have the wisdom to realise you do not know what it is like to walk in that person's shoes and never will.
Then, you might be able to help, if you want to.