I managed one of the top 100 nodes in the nineties. Two reasons made end users prefer other systems: interactive editing (wysiwyg) as in forum software transfering onto web sites and pictures.
Usenet readers to offer both features could have been developed. And running private leaf nodes (as a number of people did) would have been possible. Instead people moved to other platforms and reinvented many wheels, not always in a better version.
Archiving Usenet articles is and was easy. A forum on the other hand is a tiny walled garden and if the people running it quit, the content is lost.
For adventurous people: its still possible to get a Usenet connection, e.g. for a small fee at http://news.individual.de/ (intro page in German, but Google or Deepl will translate it for you ;-) … disclaimer: I'm just a customer myself there.
But that is a huge drawback of non centralized systems. Multiple implementations are great, until you want to develop a new feature, and then it never happens (or happens very slowly). It takes hard work to get multiple, sometimes even competing people and groups, to have a same vision or goal, and sometimes it is impossible.
And when you do end up updating, there are still people that will complain about it, forever. On this very forum, we often see people complanining that the web is not just static hypertext documents.
Does this include access to alt.binaries.* ?
We're talking mid-90s and Windows 95 made things a little better but it was still a mess because Microsoft thought they could make their own internet knockoff MSN a success. So they put much more effort into that at first. Thank God they were unsuccessful because the online world would have been even more commercial than it is now. Even now they're willing to risk the tiny market share of edge by spamming people with "special offers"
Webmail was still pretty new and not fully functional. Usenet was just one of the many things to set up. I don't think this was the reason it didn't take off.
Only if you couldn't find it after trying those, would you have to check the signup info you got from the ISP. Which also included their SMTP server, which, I mean... most customers also got email figured out just fine.
I think the larger issue is that, if you didn't get your email working, life _sucked_, everyone expected you to have it. But if you didn't get usenet working, you were the only one who suffered and a lot of people didn't even know they were missing out. So the incentive to connect simply faded.