Has the community of people who wrote documents like this just dried up and vanished? Or have they all moved somewhere underground I can't find?
They grew up. And the internet of books became the internet of videos. They're out there writing technical manuals, exising in middle age and earning money. Back in those days a place like textiles would be an aggregator on a fairly small internet. Most of those content types can be found with their own larger more focused niche sites.
You can't get more focused than textfiles. This is an online museum about a specific aspect of internet lore and history. Jason Scott is an archivist/historian.