That seems insulting to the Firefox devs. Firefox's devs are clearly better than that. The Customization page is pretty bare, they can still add it there without looking like your image.

What a time. Now every option is either a) not available b) hidden somewhere where you need the Internet to find it (chrome://flags, about:config, registry ...) and c) probably removed in the next update because "people didn't use it anyway"

The picture you posted is a positive example. An example on how to customize the software you use.