That’s been my experience too. In the early year, I remember having long conversations with different friends every night on AIM. Even some casual acquaintances ended up being good friends because of the conversation we had. I kept up with people all over the world with personal e-mail, sometimes for years.
It does seems that between 2010-14 or so, people disappeared en masse from AIM. People stopped writing back to personal e-mail. Everyone migrated to social media, even though social media wasn’t a replacement. Every thing was public, good friend and strangers being in the same bucket. Long form conversations between two people disappeared. Someone would through out something to everyone they were connected to, and you could comment or ignore it. Communication just became very public, impersonal, and shallow.