The page is so narrow, like it's made for a vertical smartphone screen. That's ANNOYING!
replies(1):
This is also related to why professional newspapers and magazines lay out text in relatively narrow columns, because they are easy to scan just top-down while hardly moving your eyes left-right.
I do think that vertical phones are too narrow for conveying decent text, but you also can't have completely unbounded page widths because people do run browsers maximized on desktop 4K screens.
The style of the page can use CSS column properties to make use of the width of laptop/tablet displays, instead of defaulting to ugly "mobile size fits all" templates.