For me an incredibly common task in web development is to have a web browser and 1 or more terminal windows tiled horizontally, side by side, in an [ A | B ] or [ A | [ B | C ]] configuration, where A is a web browser, and B and C are terminals.
In order for this to work for me on a screen resolution <= 1920x1080, the ratio ( width of A ) / ( width of screen ) should be dynamically adjustable using a single key combo, without causing window overlapping. If this ratio is fixed, and cannot be dynamically adjusted by the window manager, I experience one or more of the following problems at any given moment:
1. the web browser window is too narrow, causing wide documents to be clipped and a horizontal scroll bar to appear.
2. A terminal window is wider than 80 characters, causing unnecessary screen area to be consumed which could be better allocated toward the web browser.
3. A terminal window is less than 80 characters in width, preventing the entire line of code from being displayed.
To me Linux is the ideal laptop OS because it's the easiest OS to install a tiling window manager on, and a tiling window manager is what maximizes the platform's primary constraint: small screen area.