Why in creating a webpage we have to follow 60% of content and 40% percent creativity / design?

In creating a webpage we have to follow 60% of content and 40% for the creativity / design. Their is 60% of content in creating a webpage, so that the viewers can learn or get some information in our webpage. Then, their is also a 40% for the creativity / design to have a COLORFUL and ARTISTIC webpage and it can get some attention to the viewers.