Reducing the width of the text might be a good idea to improve readability. But some pages contains large tables, for data or just presentation, especially sport projects but not only.
When there is nothing any more on the right side (so below the infobox), these tables should be able to expand to this part, because it feels really strange to have a big tables condensed to a small size in the middle of the page when there is blank area on left and right. I'm thinking about pages like this one or that one.