This problem got solved when YouTube started allowing offline videos. Idk if it is available in your country, but in India you don't need to be a paying customer to save offline videos.
I wish we had these options in Canada, because mobile bandwidth is stupidly expensive over here.
This is because Internet in India sucks
$ brew install youtube-dl $ pip install youtube-dl
even if you don't use brew. Python is there out of the box.