By the nature of their work, developers are an organized bunch most of the time. More often than not, however, they are optimizing for efficiency rather than aesthetics. This is why they often tend to treat websites like old-timey newspapers – filled to the brim with information, but a nightmare for users to actually consume.
You want users to be naturally visually drawn to the most important information in any section of your website. Effective use of white space is one of the most elegant and time-tested ways of doing this.
Not only does white space serve to highlight important information, it also improves reading comprehension and makes your overall design look substantially sleeker. Add it to your arsenal of design tricks and your sites will instantly start looking more polished.