Hm, well then maybe an alternative to usenet maybe try the OCH-Variant. Many sites out there for the german dubbed content. An old but good site to get to some good warez sites fast is startseite.to But some old links still exist and might not be the best route to go, so still be cautios matey.
For a complete series its difficult. I guess you could copy all the links of each episode, put it in a .csv file, and let GPT write a script that opens up a Terminal/CMS/Powershell that calls yt-dlp with the parameter being the link of each episode.
Naming to be S01/E01 could get difficult but you could make another row in the .csv file and let GPT edit the script, so that after the download is complete the file gets renamed to the corresponding row.
Oooor you go the easiest way and sail the high seas, go to serienjunkies.org or other sites like this one, and go with one of the one-click-hosters, pay them and be good for a year or whatever time range you would choose.
Edit: if you have a link of the video on the arte website, you might wanna try to copy the link and put it into yt-dlp. It is capable of downloading from youtube with sponsorblock information but also capable of downloading videos from other sites. For example the ARD Mediathek or Arte.