I've been working on a small Go program to do this specifically for the lofi hip hop beats youtube stream (file here: https://git.sr.ht/~asimpson/lofibar/tree/exec-ffmpeg/item/ma...). You can pretty easily parse the Youtube page to get the HLS stream and pass that to ffmpeg. No need to even have the overhead of another browser tab then.

P.S. also if anyone knows how to statically compile ffmpeg or libvlc into go I'd love to know :)