It seems that all the utilities to downlaod audio from Youtube BEFORE download audio in .mp3 and THEN convert them to FLAC or other (that is absolutely useless).
Question: if the native Youtube file is already a HQ-Flac one, how to downlaod directly a Flac file?
Youtube is compressing audio and video. You're not hearing lossless anything on YouTube.
True. I have a feeling that these sites which claims to extract lossless formats are just adding lots of dithering to the audio file. That would not improve the quality of the audio files, which is a completely redundant process.
If you convert a lossy audio file (mp3) to lossless file (flac) it will sound exactly the same but may be larger. FLAC can reduce the size of an uncompressed audio file (wav) without compromising the sound quality..
FLAC isn't limited to CD quality. You can buy files as high as 24 bit 192khz sampling rate in flac.
There are currently two music streaming services that provide CD quality files. They are Tidal (an extra $10 per month) or Deezer. Worth it if you have good audio gear.
There is a new process called MQA that has yet to be implemented that will allow the economical and practical streaming of higher than CD quality digital files.