When there is ongoing conflict in the home the children get caught in the crossfire.
Children internalise the messages they get from their parents.
The way their parents model relationships, parenting and even the way the parents model conflict is all internalised by the child/children. They carry these messages into their adult relationships. The children are essentially being set up to have their own failed relationships and or marriages.
If the parents are consumed by their own emotional issues, children can be neglected where healthy meals are concerned.
Parents who are emotionally and psychologically damaged simply do not have the emotional energy to cook meals for the children so they pick up fast food on the way home.
Parents can also use the children as a sounding board against the other parent. This is a lot for the children to carry. Or quite often one child is used as a confidante for the parent/s. This is psychologically damaging to the child/children who are sworn to secrecy against the other parent. The psychological effects go well into their adulthood and in their relationships. Children are not psychologically developed to carry this burden.
It serves the children well to stay together if the couple are attending marriage counselling and are working on themselves and each other.
Where the parents are not fighting in front of the children staying together could work.