Overall, having the correct letter format will guarantee people that they can have the upper edge against other job applicants. All they need to do is to keep it clean and unique. There is no need to have a very extravagant cover letter. Just indicate all the essential things needed that can help them to get the job they need.
In reality, there are just some people who have developed this mania over grabbing hold of the most unique cover letter format they can find. They think that they will need all the research that can ensure their application letter achieves a desirable look. They feel that if it is not attractive or interesting enough, their cover letter format will end up being thrown in the trash bin.