I’ve had a good experience with youpak, you just take the url from whatever YouTube video you’re on and change “tube” of YouTube.com/shegaiabfvtbrbw to “pak” so it’s youpak.com/whateverwhateverwhatever and the dropdown right at the top has the download or convert to MP3 buttons right there.

I do use Firefox with an adblocker so idk if it’s a cancerous site otherwise.