I remember reading a paper which argued that the impact of divorce on children is determined by pre-divorce family functioning level. Children in low-functioning families often experience parental divorce as a relief, it removes them from conflict/violence/abuse/harm, and it can have a positive impact on their lives; by contrast, in high-functioning families, the parents do a good job of hiding their marital issues from their children, and the children often experience divorce as an unexpected, even traumatic, event, which disrupts the stability of their world, and can produce lasting (even lifelong) psychological harm. I think using that model is a good way of integrating the kinds of contrary experiences expressed in this thread.

If divorce laws were written to put the welfare of children first, they’d make divorce easy for the first kind of family and difficult for the second. However, I don’t think children’s welfare is really a priority for most contemporary divorce laws.