I think that stems from the emancipation of women, children and other family members from the old hierarchies of the 50's where the 'Dad' was the bread winner, Mum stayed at home and kids all chipped in to a whole unit and decisions were made about where folks holidayed, what they did and where folks went based on the opinion of primarily the male provider, seconded by the mother. When you have only one or two people in charge things are on the surface more close knit, whereas now everyone does far more things that they please themselves. No-one is forced to watch the one TV that one family member has paid for, people all have their own devices and thus a larger online circle of like minded friends not available to other generations. Are we less tight knit? My own family no, hit one of us and you'll see people swarming from all four corners of the globe to deal with it, rather than two doors down is all.