After some reflection I came to a conclusion that I rarely (if ever) watched anything of value on YouTube, and so the best method to make YouTube less distracting in my case was adding:

  0.0.0.0         youtube.com
  0.0.0.0         www.youtube.com
  0.0.0.0         youtu.be
  0.0.0.0         www.youtu.be
  0.0.0.0         youtube-nocookie.com
  0.0.0.0         www.youtube-nocookie.com
  0.0.0.0         ads.youtube.com

to /etc/hosts