from an absolute baseline, it is impossible to gauge family "strength."
usually what is meant is that there was less divorce, and more people lived together in the same household or neighborhood.
that isn't "strength" if there were social, economic, and legal factors that were what stopped divorce, and forced people to live together in crowded homes, slums, tenements, or neighborhoods - often cut off from progress and future prospects.
now there was something *intrinsic* to family across the board, but that was partially out of necessity, and partially a product of lack of opportunity, mand partially a product of state violence violence.
having nearby family and community familiarity is important - as a social function - but not if it papers over interpersonal violence and abuse, rigid and stifling hierarchies, or even as a preventative measure from internal progress