Never thought I would get emotional about losing an app
Girlparts@kbin.social to 
Reddit Migration@kbin.social – 166 points – I was with Reddit for 12 years and bounced between Rif and Apollo, I am sad I am losing both
You are viewing a single comment
Ehhh.
I'd timeline it something like this:
Interaction was on non-Web-based systems, mostly distributed
This was mostly pre-2000s and tended to go into decline in the 1990s or 2000s as Web-based platforms focusing on ease of use picked up users. Many of these were distributed.
Usenet (decline as a discussion forum dating to maybe late 1990s, though lots of pirated information is still transferred via it)
IRC, peaking around 2003 according to WP
Email (peaked later, in 2009, according to WP. Obviously still pretty healthy compared to the above two.
Web 2.0
People tend to shift towards interacting with each other on large websites; these tend to later acquire mobile apps to cater to smartphone users.
Facebook
YouTube
Twitter
Reddit (though a fair number of third-party clients did exist)
If the Fediverse manages to pick up a lot of people, it's probably somewhat-closer to the first phase.
IRC was great back then. The other day I jumped on Undernet because I was feeling nostalgic. It's still running but didn't have much activity. The fact that it still exists made me smile.