Usenet atrophied slowly and suffered from multiple problems, but the turning point was when AOL started offering a gateway. That's when it become obvious that

Usenet atrophied slowly and suffered from multiple problems, but the turning point was when AOL started offering a gateway. That's when it become obvious that a lot of what made Usenet work so well was that the population was small and very homogenous (making it easy to build a high-trust culture), and that neither of those were staying true. https://en.wikipedia.org/wiki/Eternal_September https://en.wikipedia.org/wiki/Eternal_September