It hasn't worked for many years. I recommend the extension: "YouTube Mobile for desktop" which is working very well.

Não funciona mais a muitos anos. Recomendo a extensão: "YouTube Mobile for desktop" que esta funcionando muito bem.

Link: https://addons.mozilla.org/pt-BR/firefox/addon/youtube-mobile-for-desktop/

does not work
Firefox Browsers
Version 83.0

Please fix the addon..

No longer works

I really like this addon but I had to ditch it yesterday as Youtube is trying its hardest to force us into the sluggish layout they have now. Since this hasn't been updated since January Youtube managed to remove the Show more button from all pages unless you use the newest layout.

Makes no speed or performance at all. Take a chance or skip it.