Nothing is an absolute. Some kids are relatively unaffected. Some are traumatized and psychologically damaged. I dated a girl when I was young that was traumatized and psychologically damaged from her parents D, including her mother's A and leaving for the OM. And her dad's subsequent remarrying. So it can happen.
There are no guarantees in life, except that none of us get out of it alive. Not all marriages can or even should be saved, not all kids from happy unbroken homes become saints, and not all kids from broken homes become disasters. I just take exception to the blanket statement that "the children will always be better off" with a divorce than with conflict-ing parents as a justification or rationalization for D, or that "the children can always be shielded from psych trauma if the D is handled correctly." Neither statement is true. In fact, IIRC, MWD makes it a point to "bust" that as a "myth" in one of the early chapters of DB-ing. Is divorce sometimes the best or only solution to a troubled marriage. Sure.... But to one degree or another, no matter what the dynamics at play and no matter how "successful" the ultimate outcome for all involved, it is almost always traumatic to the children when the parents split.
H53/W51, R-ing 4/'18
"Do not arouse or awaken love until it so desires"-Sg.of Sg 2:7
"So oftentimes it happens,that we live our lives in chains, & we never even know we have the key"-Eagles III 1:3