OT Forum screen space usage
the red parts are the white space (and ads). See how little of the page is actually useful content?
Part of this is probably because the forum only fits horizontally with a browser window of > 1024 pixels. Even though monitors are getting bigger, that's excessive as a lot of people browse with a window smaller than full screen.
Moving into the content, the unused avatar area (turned off for me wastes lots more space).