The only proper way to evaluate the sound quality of YT videos is to use a decent dedicated small desktop computer with a minimum of 8 GB of RAM - and connect it to your sound system through its high level input. Then simply view (and listen to) the videos with a small video monitor thru the browser of your choice.
Better yet, download the audio portion of the posting, and play it through the outstanding, free VLC media player - which is tweakable to vastly improve sound quality.
Finally, the built in DACs in Windows 10,11 do an excellent job of conversion - or, even install a quality sound card to further improve it. I have built a comprehensive music library this way, without "breaking the bank".
Cheers, enjoy, and have some fun with this!