While this is obviously an exaggeration, it is not too far from my own experience. I have two monitors at work, of which I use only one (the other is for pasting post-its). When someone asks me why I don't use both, my response is always the same: “I can resize and minimise windows just fine. And if I ever need to see two things at once, I have tmux for that.” I would like to have a bigger monitor, though, because old age takes its toll on one's sight.