In my experience the main factors that killed Usenet were 1) the World Wide Web and 2) spam.
1) Usenet was at one point a huge portion of internet traffic. But as the rest of the web ballooned in popularity, what was originally the big fish in a small pond became a small fish in a huge ocean. Eventually newer internet users skipped the Usenet experience entirely. And the zeitgeist went with them. People who spent time putting new information online stopped making newsgroups their first choice and started doing it on their own weblogs or on siloed websites.
2) As newsgroups hollowed out, the S/N ratio went way down. I think once they were about 30% spam, people just started giving up en masse.
There's also the contributing factor of the old ISP services dying or morphing into media providers. Usenet was dialup friendly and the old 300/600/1200/2400/4800/9600/14400/19200/38400/57600 Kbps modem-serving ISPs would advertise their Usenet feed as a perk. It was 80 character, monochrome screen friendly. Once dialup became superseded by broadband, and computers turned into media and 3d gaming devices, and Napster/Limewire/eD2k made binary distribution so much more convenient for the masses, Usenet lost its raison d'être.
> Usenet was at one point a huge portion of internet traffic.
Usenet posts were just text that may have been several kilobytes in size at most. If you look at binary newsgroups, the current level of internet traffic is quite large[1] (though that was 12 years ago and is by now multiple petabytes per day).
The size of the daily Usenet feed is up to over 200TB a day now, even more than the 9TB number in your link. Although I imagine the total daily amount transferred by users is going to dwarf the size of the feed, one might still note for reference that total daily internet traffic is about 3EB which is around 15,000x that of a single full news service.
In other words, good point! I hadn't realized that in nominal terms, Usenet was still growing like topsy (albeit likely shrinking as a total proportion of global traffic).
1) Usenet was at one point a huge portion of internet traffic. But as the rest of the web ballooned in popularity, what was originally the big fish in a small pond became a small fish in a huge ocean. Eventually newer internet users skipped the Usenet experience entirely. And the zeitgeist went with them. People who spent time putting new information online stopped making newsgroups their first choice and started doing it on their own weblogs or on siloed websites.
2) As newsgroups hollowed out, the S/N ratio went way down. I think once they were about 30% spam, people just started giving up en masse.
There's also the contributing factor of the old ISP services dying or morphing into media providers. Usenet was dialup friendly and the old 300/600/1200/2400/4800/9600/14400/19200/38400/57600 Kbps modem-serving ISPs would advertise their Usenet feed as a perk. It was 80 character, monochrome screen friendly. Once dialup became superseded by broadband, and computers turned into media and 3d gaming devices, and Napster/Limewire/eD2k made binary distribution so much more convenient for the masses, Usenet lost its raison d'être.