By the 1970s, Americans engaged less with others compared to previous decades:

But in the 1970s, the U.S. entered an era of withdrawal, as the political scientist Robert D. Putnam famously documented in his 2000 book, Bowling Alone. Some institutions of togetherness, such as marriage, eroded slowly. Others fell away swiftly. From 1985 to 1994, active involvement in community organizations fell by nearly half. The decline was astonishingly broad, affecting just about every social activity and every demographic group that Putnam tracked.
What happened in the 1970s? Klinenberg, the sociologist, notes a shift in political priorities: The government dramatically slowed its construction of public spaces. “Places that used to anchor community life, like libraries and school gyms and union halls, have become less accessible or shuttered altogether,” he told me. Putnam points, among other things, to new moral values, such as the embrace of unbridled individualism. But he found that two of the most important factors were by then ubiquitous technologies: the automobile and the television set.
Starting in the second half of the century, Americans used their cars to move farther and farther away from one another, enabling the growth of the suburbs and, with it, a retreat into private backyard patios, private pools, a more private life. Once Americans got out of the car, they planted themselves in front of the television. From 1965 to 1995, the typical adult gained six hours a week in leisure time. They could have devoted that time—300 hours a year!—to community service, or pickup basketball, or reading, or knitting, or all four. Instead, they funneled almost all of this extra time into watching more TV.
Television transformed Americans’ interior decorating, our relationships, and our communities. In 1970, just 6 percent of sixth graders had a TV set in their bedroom; in 1999, that proportion had grown to 77 percent. Time diaries in the 1990s showed that husbands and wives spent almost four times as many hours watching TV together as they spent talking to each other in a given week. People who said TV was their “primary form of entertainment” were less likely to engage in practically every social activity that Putnam counted: volunteering, churchgoing, attending dinner parties, picnicking, giving blood, even sending greeting cards. Like a murder in Clue, the death of social connections in America had any number of suspects. But in the end, I believe the likeliest culprit is obvious. It was Mr. Farnsworth, in the living room, with the tube.
There are more details on this in Bowling Alone. This also reminds me of the famous sociology Middletown studies that found the widespread adoption of the automobile allowed people to drive off and do their own thing. For example, they could take a drive into the country on a Sunday morning rather than go to church.
This is also something Jonathan Haidt tried to get at in The Anxious Generation: take away smartphones and you have preexisting social issues in the United States where social interaction had already changed. Yes, the smartphones may affect people and interactions but they are not the only or initial culprits to changing social conditions.
So would the answer then be to limit or eliminate cars or television? I have heard this argued before. Would these changes limit individualism in significant ways or would the trends in that direction just find other outlets?