That's one of the most important thing most people ignore: they means we can have our PERSONAL aggregator instead of using someone else algorithms and censorship. Sure at usenet time (or back at Xerox time where these concept was implemented for the first time in known history) the level of scoring and self-censoring technique was limited but nowadays it's a CENTRAL point. Usenet is a decentralized network no one own, no one can really censor at a whole and aggregators who are needed for anything high volumes are personal things, posts can be archived locally so they do not disappear and so on.
Coupled and integrated (like Gnus offer) with RSS feeds mails and in the case of Gnus also HN (nnhackernews backend) or Reddit (nnreddit) we can have a CONSISTENT and LOCAL UIs for ALL our public information/communication infra in a robust yet simple manner. That's the classic nuclear war resilient internet vs the modern centralized and censored web.
Oh BTW usenet today it's almost abandoned, but some have rediscovered it for mostly piracy as an alternative to bittorrent. It's relevant because it means that while normally binary groups in a modern world are a bit odd they perform well enough for such big file sharing usage.
Or, long story short: evolving these tools we can have a modern classic desktop who happen to be a human PERSONAL exobrain, work desk, tool, with the human at the center. With the modern web and relevant WebVMs we get instead modern dumb terminals of modern mainframes.
Do you prefer owning nothing "and being happy" like the infamous WEF/2030 video OR you prefer own your small slice of the world peer between peers?