The vast majority of files on Textfiles.com came from BBSs in the 1980s and early 90s. The founder, Jason Scott made an awesome documentary about the BBS days. Steven Levy also covers the time and the scene somewhat towards the end of his fantastically detailed book “Hackers”
Jason regularly streams his archiving activity on Twitch under the username "textfiles". It's usually a quiet stream- he's been digitizing a lot of videotapes recently.
The Jason Scott documentary is highly recommended. I knew Ward Christensen and Randy Suess, they were pretty interesting people. (RIP Randy, he passed away near the end of 2019)