Usenet never stood a chance. It was invented in the days when net access was something of a privilege that could be revoked if a user did not behave in a socially acceptable way. As such, it was acutely vulnerable to spam and abuse. What proportion of Usenet traffic consisted of porn and pirated binaries in the late nineties? Is it any surprise that ISPs ,fearing they might be held accountable for distributing such material, started cutting off their Usenet service?
The good news are: Usenet still exists. There are free NNTP servers that host most non-binaries groups. Many groups are abandoned, but some are quite lively. Every time I visit, I am struck by the fact that no website forum approaches the ease of use of a good threaded newsreader, and I am amused when I see each new generation of coders, ignorant of the past, trying to re-implement an incomplete, flawed replica of what once existed.