Still kinda scuffed for me but it seems more consistent before a stutter, dunno if audio and video are actually synced but it should be
You'll need mpv+yt-dlp and to embrace the way of the terminal as well as get an extension to download the cookies from youtube in netscape format
Swap out Downloads/cookies.txt to whatever the location of the cookies file is, you can change the formats as well but I've got it set to 232(720p) and ba(best audio)
mpv --ytdl-raw-options=cookies=Downloads/cookies.txt --ytdl-format=232+ba
https://www.youtube.com/watch?v=x3yYh4x-xCw 