[ArkyBeagle]

Usenet was pretty much utterly anarchic. It faded. I'm still not completely sure why - the people who got off of it can't really say. Perhaps it's as simple as port blockers on corporate networks and people going around corporate networks with phones.

[spc476]

Spam, AOL (https://en.wikipedia.org/wiki/Eternal_September) and the high cost of hosting the binary groups are mostly responsible for the decline of USENET.

I know I slowly stopped reading it as the spam and new customs (top posting, not trimming posts) crept slowly in, and most of the action switched to web forums (because of shiny HTML and what not).

[ArkyBeagle]

I keep forgetting about binaries.

Even if your ISP dropped NNTP, there were still free NNTP servers around, so I'm less than agreed about that expectation. And the Eternal September was in 1993. Usenet was "viable" well past ten years past that.

I think the best explanation is "new shiny Web" although about... half of the folks I used to read on Usenet are now on Other Fora and it's nowhere near the same - it's not a substitute.