Perhaps, I’ve never really kept track of that content on usenet. But without usenet/torrent support that does make this *arr app kind of incompatible with the rest of the *arr ecosystem, just seems like an odd design choice.
I don’t look for that type of content too much but usually I’d just download packs from public torrent indexers e.g. Nemesis43 / Nem43 still uploads to 1337x and Demonoid. Those torrents often get mirrored to TorrentGalaxy too.