Doesn't require an account, or app, or plugin, and works non-intrusively without an adblocker.
Lets say you want to grab "I Can't Play Piano, Pt. 1". This is usual the youtube link:https://www.youtube.com/watch?v=DTQEVXLAfc4
A small edit to the URL will redirect you to y2mate. Add "pp" after the "e" in YouTube:https://www.youtubepp.com/watch?v=DTQEVXLAfc4
Links to download the video or stripped audio are provided. Works on PC and mobile.