The "old ways of family life" are NOT nuclear family, and are incompatible with that concept. Throughout history, most civilizations have lived and raised their children in extended families (or other community/group arrangements), not nuclear families. The switch from extended family to nuclear family become viable only during/after industrial revolution.

A separate couple rising their kids is not 'traditional family' - a traditional family would delegate significant parts of the childcare effort away from the young adults/parents, so they'd focus on their work; a nuclear family doesn't do that.