It is very easy for me to establish a virtual third space for a topic of interest, but the reality of timezones make establishing connections with those friends sometimes insurmountable; and those friendships do not translate well to the physically limited world.
Conversely, local relationships are also extremely difficult to establish due to the diffuse living areas surrounding larger cities. Those whom you might be inclined to establish a social relationship with can live /hours/ away during the evening commute periods and are often extremely busy on weekends.
Even if time to meet up can be established a stable and sufficiently (warm/private/intimate) meeting place might not exist or might require an economically infeasible increase in rent. The inhospitably to cars (for outsiders of the urban core) and the low quality of public transit in US cities (particularly 'out west') compound the pain of this friction.
The net result is friction on social activities that destroy network effects that are probably expected in larger populations. When combined with a lack of locality stable careers in many fields, at least first hand, I observe a lack of community and the ability to establish social links.