Earlier quoted context omitted.
It still exists. Currently it looks like Patreons and their associated communities, long-running web forums, small chatrooms on platforms like Discord or Facebook or Instagram, and so on. Small communities, with relatively high barriers to entry.
That's not the same Internet. Patreon, forums, Discord, Facebook, Instagram and so on are all centralized. With the Internet of the 90s, discussion happened with decentralized Usenet (owned by nobody) with more-focused discussion happening on mailing lists (literally owned by whoever was smart enough to get Majordomo compiled and running). Email was handled by individual ISPs or other orgs instead of funneled through…
The technology doesn't matter, it's changing all the time. The difference is the size of the community, and the barriers to entry. If these communities were easy to discover and join and hard to be booted out from, they wouldn't be protected from The Slop. It used to be just getting on the Internet was the barrier. Now we need new barriers: paywalls and word-of-mouth and moderation.