[littlecranky67]

Just guessing, but the legal situation in Germany is perfectly clear: You are free to download any content from streaming platforms as long as it is not an "obvious illegal source". Youtube being a subcompany of Google/Alphabet clearly does not qualify as "obviously illegal". The catch is, that it is still illegal in Germany to bypass copy-protecting measures. I.e. if you would rip a Netflix stream that uses Widivine/DRM, that would be illegal. I think this is the argument they used in this court case, although I was not aware that youtube videos use browser DRM.

[doodlesdev]

   > although I was not aware that youtube videos use browser DRM

I'm pretty sure they don't, at least not for all resolutions. I'd never install Widevine into my main Firefox, but I watch YouTube daily though it. Perhaps the copy protections are more security by obscurity (i.e. weird endpoints, weird parameters, arbitrary requirements, etc.) although I have absolutely no idea since I've never read yt-dlp source code.