The main reason to completely disconnect is that it frees you from being a part of the others persons dysfunctional way of interacting. This is especially true when the other person just continues navigating in a dysfunctional way and expects others to just go along with it.

This is often what addicts practice which is so unhealthy. Even for those who get sober, they have to really work on changing their dysfunctional habits while self medicating. And part of that is developing a habit of blaming others when things don’t work out. It requires actually growing up instead of just self medicating when challenges arise. And being willing to see ones own part of the dysfunction.

Your father is not interested in recognizing his dysfunctional behaviors. When it comes to that kind of person even if it’s a parent or family member a complete disconnect is necessary.