Putnam ascribes ~25% of the drop in social capital over the past 70ish years to television's rise, but not because of fragmentation of visions of reality as you suggest. Rather, it is due to TV soaking up time that might be used to build community and social cohesion. See below for an example quote and corresponding link that goes into more detail.
"Even though there are only 24 hours in everyone's day, most forms of social and media participation are positively correlated. People who listen to lots of classical music are more likely, not less likely, than others to attend Cubs games. Television is the principal exception to this generalization--the only leisure activity that seems to inhibit participation outside the home. TV watching comes at the expense of nearly every social activity outside the home, especially social gatherings and informal conversations. TV viewers are homebodies."
"Even though there are only 24 hours in everyone's day, most forms of social and media participation are positively correlated. People who listen to lots of classical music are more likely, not less likely, than others to attend Cubs games. Television is the principal exception to this generalization--the only leisure activity that seems to inhibit participation outside the home. TV watching comes at the expense of nearly every social activity outside the home, especially social gatherings and informal conversations. TV viewers are homebodies."
https://xroads.virginia.edu/~Hyper/DETOC/assoc/putnmtv4.html