Somewhere, however far down, on the list of why people feel socially isolated these days is surely the disappearance of internet fora where one could discuss serious issues in a longform-text format with other identifiable regulars who could become chums or friends (albeit of the long-distance sort).

The IMDB boards that brought cinephiles together, the Lonely Planet Thorn Tree forum that was one of the most informed and unspammed places to discuss travel, the music boards on Amazon prior to about 2010 -- all shut down by corporate owners due to the cost of moderation or the inability to strictly control their brand image. Things like Reddit are a pale substitute and full of pathologies.

Thank goodness for Internet Archive!