Tyler Cowen goes into this in his book The Conplacent Class. Some interesting data he works into the theory: home interiors have gotten better while exterior architecture has gotten worse and is valued less, fewer teenagers are getting driver’s licenses, lots of recent tech innovation has made staying at home more attractive (on-demand streaming, flat panel TVs, internet in general, food delivery and Amazon).
My friends and I seem to go out a lot less. It's more fun to 'tailgate' at home with takeout and a nice TV. Going out to the bars is a lot less appealing than hitting up the liquor store. It's so much more fun to get wine drunk and order random stuff on Amazon than it ever was to go to the mall. Going to the nice grocery stores and cooking for each other has pretty much replaced fine dining. We used to hit up the barcade pretty frequently but retropi has got us covered. A lot of spontaneous hangouts take place on Discord where we're not even playing games. Why would we want to go to a movie theater and pay like $28/person when I can make boatloads of fresh popcorn, grab some bulk candy, and make extra plump weenies with our nice TV and surround sound? Video game nights have replaced things like bowling.
It's not that we're being less social, it's just that stuff at home-ish is a lot more worthwhile than the typical canned activities. Plus, doing something in the same room as other groups od strangers wasn't really being all that social anyway.