[xjay]

To turn it around; maybe browsers don't utilize space very well?

Imagine if we could divide a tab into regions of sites instead?

Having a maximum line length is the humane thing to do, unless the person has phobias of empty spaces, of course. :>

The links you provided are not for the user, but for the designer. Text, however, is a global means of communication, so it should get better treatment, and care in general. Especially by browsers.