But without smartphones you had no choice but to sit at home on the computer.
you are 100% right. Was reading this book called The Nineties this week and it discusses that shift in a different way, but basically the idea that people moved from being online and annymous (like we are still) to online with their actual real name and face, which brought it away from the kind of nerds that everyone thought "online people" were.
and at least partly that whole idea that being online meant sitting home at a computer means it was "nerdy", or socially undesriable. Once you got around that, it turns out people wanted to interact digitally and create their whole characters online.
Posting on forums like this was a precursor to social media, but the annonymous part plus the idea that we mostly talk about subjects, as opposed to our day to day lives, complete with avatars and alter egos. Smartphones took that into the real world.
We basically showcase a form of our identity, I remember answering questions for some other rap profile 20 years ago, favorite producers (Kanye and Just!) age, favorite rappers (Nas and Jay-Z)