I don't think this is true. There has been an explosive growth in cultures which are interest based rather than location based. Board games, furries, car people, kpop, etc. These groups all have their own inside jokes, terminology, events, etc.
What has been lost is gathering a random sample of people in the same city and them all being on roughly the same page about culture.
What has been lost is gathering a random sample of people in the same city and them all being on roughly the same page about culture.