I think it depends very much on the individual circumstances of the family. There isnāt a one-fits-all answer, solution or conclusion. The parents do have a responsibility however; itās towards the children, regardless of their own relationship. Some couples who get married seem to overlook this basic concept.
If the parents donāt like each other anymore, then I can only hope that the parents have the intelligence to figure out whatās best for the children. Stay together for the children, or devorce for the childrens sake. Many parents donāt seem to have the required level of intelligence, and many seem too busy getting one over on the other parent to notice the children.
On a different note though, there was one couple in my extended family that was reasonable open with their children regarding why they will be staying together instead of divorcing. Then when the children reached 15 & 16 years old, it was the children that said to their parents, āI think itās now time for you to get divorcedā. Later, the woman said to me that it felt as though the children were divorcing her. At first it really upset her. I said to her that maybe she did the right thing in staying with her husband for a several more years, because her children when younger might have felt that she was divorcing her children.
Some adults need to grow up and partake in the real world that they have created for themselves & the young people around them.
If the parents have messed up their documented contract to each other, they then shouldnāt mess up their unwritten contract they have to their children.