What makes family drama "solid" is the presence of conflicting emotions. If two people just hate each other, it’s a feud. If they hate each other but still feel obligated to show up for Thanksgiving, it’s a family drama.
Family drama is the bedrock of storytelling because it taps into a universal truth: you can’t choose your relatives, but you can’t easily escape them either. Unlike a typical hero-versus-villain arc, the "antagonist" in a family drama is often someone the protagonist loves, making every conflict a high-stakes emotional minefield.
Family units often operate like miniature political systems. When the "head" of the family (the patriarch or matriarch) dies or loses power, the resulting scramble is a goldmine for narrative conflict.
These roles are often assigned in childhood and followed into adulthood. The drama arises when a character tries to break out of their box, but the family refuses to let them change.