This is more complex than you might thing. First, there's far more places to meet people - rather than having them over for coffee, we meet in a coffeeshop. Networks have provided a "together in time" alternative to "together in place", so people can game, talk, ... via voice and video rather than traveling to a common location. There's far more 2-working-member families than previously, so the ability to organize household events is reduced. Finally, there's far more organized sports activities that consume both child and parent time. These pull everybody out of the house.
I can assure you we had "coffeeshop"s in the ancient times.
Decline in religion + third spaces combined with socioeconomic system expectations of a 40 hour work week + two incomes needed to live comfortably. Places and time for community and social activities has declined, and so social activity has as well.
If more social time is desired at the macro system level, people need to have more leisure time (shorter work week, higher wages, good quality of life with more free time broadly speaking) and more third spaces to meet and socialize.
Citations:
I’ll never forget a conversation I overheard on a plane years back: a caricature of a man in his 20s failing repeatedly to explain to an older lady what a “gastropub” was. Each time, he rephrased his description, and each time she responded, “that sounds like a pub.”
“No, not exactly...,” he replied in an increasingly exasperated tone. I could hear the struggle in his voice as he recognized the cracks forming in the thin veneer of his identity. “It’s like a pub, but it serves food. Like, real food, thoughtfully considered by a gastrochef.” She returned the serve, now teetering on boredom at minute four of the flight. “At our pub we call him Kevin. He makes the best pot pie.”
He regrouped and they found truce in talking about the weather in Toronto. I resisted the urge to twist around to ask if they knew any good restaurants downtown.