I don't think there is any doubt that children are better off in a family where the parents are together and are happy, healthy, respect one another and enjoy being together. The question becomes how many long-term marriages fit that equation? One of my best friends has been married 25 years and has 5 kids and right now is staying married for the children. His house is very toxic because they fight with one another and call each other names and can't stand the fact the other is breathing. Now whose kids need to be more resilient his or mine? Mine go from one house where there is peace and love to the next house where there is peace and love.
Both my parents and my exw's parents were/are in toxic marriages. Guess what we both brought into our marriage?
There are good divorces and there are bad divorces. The ones where the children struggle are typically (but not always hence the use of the word typically) because one or both of the parents aren't holding up their end of the bargain of putting the children first. When the children get dropped off and picked up a police station the children are more than likely going to have to be resilient.
My children feel loved by both of us, they know that we are there for them, they have each other, and that is more than enough. Believe me it is.