There is no perfect situation or solution. Abusers come in all shapes, sizes, and ages. Grandparents can be abusers, parents can be abusers, so can any adult that a child comes into contact with during their childhood. The most common abusers are step parents, or partners who are not the child’s natural parent, particularly males, but also females on occasion.
More commonly, some parents use their children to abuse their ex partner, and are obstructive with regard to anything and anyone in the child’s life. This is not to hurt the child, it is to hurt and control the ex partner. Sometimes grandparents are also included in this, and it seems to me to often be the paternal grandparents who suffer from this scenario. However, I’m not an expert. Perhaps the courts should consider the whole of the child’s life, people who were part of the child’s life before the parents separation and are important to the child. However I am very much aware that the courts are absolutely overwhelmed with cases such as these and trying to sort out parental access is difficult enough.
Anyway it’s not going to happen anytime soon.