Doesn't this also mean that the server can be a single point of failure? Whereas in a torrent swarm it's distributed and more resilient?

It's also a fscking mess to set up a Usenet downloader, especially since it'd be a bunch of buggy weird stuff ending with -arr in the names and web UIs.

And no, torrenting isn't outdated and isn't amateur. In Usenet messages are replicated over all services offering that newsgroup. I hope the downsides are clear.

Some kind of Usenet with global identifiers of messages and posters, and with something like Kademlia to find sources for a specific newsgroup(to get all the other side has in it)/post(to get it specifically)/person(their public key), would be much better than just replicating each message everywhere with a local identifier.