Can't help but wonder what the sound quality of a downloaded youtube vid converted to mp3 would be vs a straight up mp3 or FLAC.
YouTube-dl provides the list of all the available formats. You choose the desired quality.
youtube-dl's name is unfortunate since it.grew.to support many other sites, such as SoundCloud. You can download flac or wav files often using it on SC content.
Looks like it's time for you to learn about the magic that is youtube-dl. It will change your life.
Bad. Lossy -> Lossy transcoding will always introduce artifacts. Unless the origin source is lossless. (Actually lossless, not a file someone transcoded to a lossless format from a lossy origin)