Usenet is basically a forum so that’s where all the benefits lie. Files are split up into multiple parts and then propagated to various servers. So, just like BitTorrent, you’re downloading a file from multiple places at the same time and also are downloading multiple parts of the file at the same time.
The difference, though, is that, whereas with BitTorrent you’re reliant on the speed of someone else’s internet connection and the hope that enough people have enough parts of the file, Usenet files are hosted on dedicated servers and every file is mirrored to every Usenet mirror. These are typically dedicated connections too so the speeds are nice and fast.
The other less-used benefit is that BitTorrent files don’t really have a way to recover a download if the source file is corrupted or incomplete. If you download a file from a torrent and one of the users seeding has a corrupted part, you have to verify the contents of the file and then your client has to find a valid part to download from. This isn’t a big deal but can be a problem when a file or torrent has few seeds. With Usenet, your download comes with Parity (.par) files. These files are checksums that allow you to recover any number of parts or files so long as you have enough .par files downloaded to cover the number of pieces missing. This means that you can download incomplete archives at any point and you’re never reliant on other users since the .par files are also uploaded by the initial poster.
Both have their benefits and drawbacks but Usenet mostly wins on the first-past-the-post timeframe. BitTorrent probably wins as time goes on because it’s very rare for a torrent to have bad pieces or anything after the first day or 2 of the initial upload. Also, most scene releases are posted to Usenet first. So, if your concern is getting released as soon as possible, Usenet wins. If you want ease and not a lot of fucking around, BT wins.