Usenet is usually a lot faster, for most things you can basically max out your bandwidth (or whatever the max you set your download client to) instead of it being determined by the number and quality of seeders. Newer releases torrents also download very fast, but after a few months or years the seeders drop off a lot, usenet is always the same speed even if it's super old and most keep stuff indefinitely or for 10-20 years or so (longer if it's being grabbed a lot still)

Also one nzb site is usually enough, you don't need to check a bunch of different torrent sites since it's basically one massive one. I use prowlarr so I have it check nzbgeek for everything first and a bunch of torrent sites as backups in case it isn't there, but almost everything gets grabbed from usenet

Hard to find scene releases are sometimes only available via usenet.