That's true, although e.g. qutebrowser still displays the current URL because it has a small status bar anyway, so it just uses the remaining space for that. It

That's true, although e.g. qutebrowser still displays the current URL because it has a small status bar anyway, so it just uses the remaining space for that. It doesn't have to be as large as in many common browsers though, I agree. Whenever I install Firefox somewhere the first thing I do is remove half of the UI from the top area. I really, really love that FF has this feature.