Or just use Pale Moon, which is privacy respecting out of the box and doesn't need any hardening bullshit because it doesn't have any analytics, telemetry, third party crap like Pocket or anything else built in. It is what Firefox would've been if they didn't discard their original powerful XUL extension system and epic customization that doesn't need you to only dick around with userChrome.css (though you can if you want).

And with Firefox, the point is not that you can disable these features in about:config (until they remove that ability a few versions later) - the point is why the hell should you have to do any of this for a browser that keeps claiming to be privacy respecting?