And moderation came _very quickly_. Usenet started seeing significant use in 1983. The first moderated Usenet group was created in 1984 (insert mandatory weak Orwell joke). And Usenet was eventually largely replaced by very heavily moderated webforums, and then by things like reddit where the popular subreddits that people actually want to use are mostly fairly heavily moderated.

It turns out that people don't, as a general rule, actually enjoy using totally unmoderated fora; they tend to quickly fill with spam and awful stuff.