I think you're missing the point. The text should always automatically adjust to the font
size and available width. A column of text should never be wider than the screen, because
then you have to scroll back and forth horizontally to read each line. (I personally don't
mind if the overall layout is larger than the screen as long as the text column fits within
the screen width.) Some people with poor vision do not have the option of using a smaller
font, so it is also an accessibility issue.