The problem with your preferred solution is that it requires changing the window width for each web page. My web IRC client requires a somewhat wide window, sin

The problem with your preferred solution is that it requires changing the window width for each web page. My web IRC client requires a somewhat wide window, since it has a sidebars of channels on the left and a sidebar of users on the right, both of which provide utility and I don't want to hide. Reddit is unreadable on narrow screens. But blogs would need an 80 column window (I.e 1/4 the width of the screen) to be comfortable, unless the blog has some sidebar which makes that too narrow. I don't know about you, but I switch between tabs frequently, and I'm extremely happy that I don't have to resize my browser for every tab switch. I keep my browser window maximised (usually on a secondary screen). I like that all web pages are more or less readable in that configuration.