I agree with both of you, really, both interfaces are shit. Chrome has that hideous whitespace that's wasteful even for touch interfaces, let alone for mouse+keyboard, and Firefox has a cumbersome and too basic interface. I can't even do an advanced search on my bookmarks.
It's actually a selling point for me, I just can't stomach all the material design craps that Chrome forces on me where a page lost like 70% of usable space to useless whitespace.