Interesting and poignant thread. Both my parents are dead now - Dad went when I was 23, Mum when I was 42. I never had a beef with either of them of any import, I did have a period of not talking to my Mum for a bit in an attempt to get her to call me once in a while. I caved first. My ex, on the other hand, had a far more turbulent time with her parents. She ended up breaking contact with her Mum, but reconciling with her Dad (they'd divorced decades before) and now has an excellent relationship with him. I found the time she wasn't in contact with him difficult (he'd been like a dad to me) but understood her need to break away from his sphere of influence, which could be manipulative and divisive at times. Age has mellowed him considerably and given him a greater understanding of my ex's (and her siblings) experiences, but if he hadn't had a softening of heart and striven for some understanding and actually owning his part in events, I doubt she'd have the relationship she now does.
There's no guarantee that parents will act wisely, or even lovingly, toward their offspring. Same for siblings, where rivalry and jealousy, real or imagined, can dominate. All too often I've seen acting out that has far more to do with projection and controlling behaviour than acceptance and love. In those cases it can be impossible to square the circle of familial loyalty and self-preservation. Often, though it hurts, separation for self- preservation is the only way forward. Some kind of family therapy can help, and I personally have experienced individual therapy that helped me massively in understanding the dynamics of my extended family - but how may go for that, or can afford to?