Asking someone to download and install a Usenet client then set it up to connect to a server of their choice and then subscribing to newsgroups is way above and beyond what most people are willing to do in 2023, sadly.
This is not true at all. People download phone clients all the time. And there were also Usenet web clients. Subscribing to newsgroups is exactly the same as subscribing to subreddets or kbin magazines. And you have to pick a server for Fedverse also, but the the Usenet server doesn't matter at all like a Fedverse server does.
The only reason people don't use Usenet is because the free servers disappeared and ISPs no longer provided it with your internet service.