The problems with Usenet have become a nightmare AFAIC. Too much spam, too many ISPs blocking access, too little centralised control, to name just 3.

Web forums don't suffer as much from these problems. ISPs aren't going to block port 80, since as far as they are concerned the 'Internet' means 'web and email'. The fact that forum boards are privately owned allows the owner to maintain better controls against spamming, and also allows for better identity validation than Usenet. Other benefits include better linking to other hypermedia.

A nostalgic part of me laments the decline of Usenet's importance. But the reality is that web forums can be better.