My understanding is that it's takedown was due to fact that youtube-dl "bypasses technical measures that control access or copying of copyrighted works". I don't see how youtube-dl could be considered a "circumvention tool" if the end user of said tool would have access to the content if they used a web browser instead.

out of curiosity (and total legal ignorance)" wouldn't that logic make chrome also illegal? since it's a tool that can be used for circumvention as well. If the defense is that it's not chrome's intended purpose, then one could argue that the defense also applies to youtube-dl since its intended use isn't necessarily to download _licensed_ videos.