Usenet thrived in a time where most of us trusted each other, traffic was an order of magnitude lighter, trolls were few, spam was unheard of, and moderation - if any - was cheap and painless. I honestly believe those times are past us. And I say that as someone that loved Usenet back in the day. What you're asking for, for free , isn't possible.
> spam was unheard of Eh, not exactly ;) There was (and probably still is where needed) an elaborate system of killfiles being exchanged among trusted nntp servers. Also, you might want to look up the origin of the word spam: > The first time that the word ‘spam’ was used in this sense actually arose from an innocent-enough affair. In 1993, Usenet administrator Richard Depew was responding to a discussion group, but…
https://en.wikipedia.org/wiki/History_of_email_spam
In my .edu world the most annoying part of email was “chain mail” in which each recipient was threatened with bad luck or similar if they didn’t forward it on to three others. Email loops caused by .forward files were fun too.