Of all the early internet, I do miss Usenet the most. So much of it worked because it was really managed by sysadmins - if someone was a problem, spamming or griefing - was to simply email the sysadmin where they were posting and the admin would usually block them from Usenet. As public internet as a utility became a thing, the bigger isps couldn't manage at that scale. There's more to it, but as the sysadmins lost control, usenet was overwhelmed by spam.