I would bet that the people who are saying that it's faster are probably not downloading from private trackers to a seedbox. I have heavily used private trackers and Usenet. Using both methods, the limitation is the speed of the hard drive on my seedbox. I could upgrade to a solid state drive but I prioritize storage space over speed. I can already grab pretty much every thing I want in a matter of seconds.

As for retention, torrenting beats out hands down. 5000 days is a big retention for usenet. I'm on several trackers with hundreds of torrents that have active seeders that were uploaded over 10 years ago... If you're using public trackers, then Usenet wins.

In my opinion the benefit to Usenet is not having to seed. I have a killer ratio on every private tracker I use. But sometimes I want to download something and I want to delete it right after. The real GOAT is to use them simultaneously. Pay for a couple of cheap Usenet providers (on different backbones) and get an affordable seedbox and put both torrent trackers and Usenet providers in Sonarr and Radar and you're gonna have a good time.

If you don't want to pay for a seedbox, Usenet is better since torrenting is slower through a VPN. You don't need a VPN on Usenet because, the servers you download from are the same that you gave your credit card info from.